I was actually thinking about submitting one of my papers in a conference which is to be held in Spain (LATA 2014) but alas I might not be able to do so since the registration fees for this conference is 400 Euros (discounted since I'm a student) which is virtually impossible to afford (since in addition to the registration fees I will have to travel to Spain as well). In fact just to get a sense of how much money this is, this 400 Euros is almost equivalent to half the salary (in terms of basic pay) a senior professor earns in my country (India) and I see that this conference is not the only one when it comes to such high fees. What are the real reasons behind such high fees? Isn't this in some away discouraging genuine contributions in academia?
Typically the fees are to cover the facilities of the meeting including services attached to the venue. In addition there may be administrative costs for the conveners to be added to that. My experience says that everytime you let a professional conference center and staff organize a meeting it becomes very expensive. this may seem like a bad ideabut what is often not seen is the work volounteers would have to put in if you tried to organize a large conference without such help. Free help is usually not easy to muster these days.
So while I agree that conference fees may seem ridiculously high at times the reason is that it would be hard to organize them otherwise. It may be easier for recurring conferences since they can build a knowledge base and tools to help but for a one-off the ask can be too large without professional help.
By keeping a discussion open about these costs we can perhaps put the spotlight on the problems and realize that we cannot both have the cake and eat it. In order to reduce costs meetings may have to be organized in simpler venues and by more volounteers from the community.
Unfortunately, it is expensive to run a conference. You have to rent the venue, provide food, possibly pay for a keynote speaker, and pay for other incidental costs.
Furthermore, as you note there is a disparity in salaries between developed and developing countries, and this can price out participants from developing nations.
I don't believe there is an institutional discrimination against academic contributions from developing nations, but your inference that it is harder to make these contributions because of a wage/price discrepancy and the need to attend a conference to be published in it is valid.
One option that might be helpful is to try to publish in journals, which do not incur travel fees. Not the best answer, I admit, but something to consider.
Finally, this is a discussion that you should have with your university -- it is in their interest to help faculty and students get published, and there may be money for travel and conference fees that the university can help out with. Furthermore, research grants (often also harder to obtain in developing nations, unfortunately) should be set up to pay for conference fees and travel, and faculty members should do everything they can to compete for grant money.
First, some practical side notes.
I'm in a field with high conference fees as well. However, my professor once complained with conference organizers when student fees were 250 € saying that no student (and no institute paying for the student) could afford that. I got in at a much reduced price.
However, I once attended a conference in Africa where many "speakers" didn't show up after they had tried to make the organizers completely waive the fees and pay their travel a week or so before the conference. The organizers felt blackmailed and refused (I believe they had a developing countries discount from the beginning, but I'm not entirely sure. Europeans paid about what you'd pay for a conference in Europe)
You may be able to negotiate a discount for not attending the conference dinner, tourist program, etc. (though I recommend attending if possible: this is where you can talk and get to know people)
Some conferences and/or professional societies have travel grants for students. Some universities have travel grants as well. They would usually help towards both conference fee, flight ticket and housing at the conference location. Ask around.
In my field (analytical chemistry/spectroscopy) in terms of conference fees for students I found that conferences in the US had much lower student fees compared to Europe.
Some more points on the costs:
you mention that the 400€ is half a months salary for a prof in your country. But the costs of living and the wages are not the same all over the world. You don't get as far in Spain with 400€ as you'd get in India. Unfortunately I guess from India most good conferences will be in crazy expensive countries.
However, I've seen conference announcements in southeast Asia and northern Africa, and the fees were not that much lower compared to european and north american locations.
I just had a discussion about this last night and the conclusion is that it's pretty much a reverse Robin Hood thing: tax the poor (with no grants) to pay for the elite (who have major grants). Meaning, a large part of the exorbitant fees consists of money to pay for the travel and lodging of the plenary speakers -- Plenaries in my view being the least interesting part of the conference, as the speakers, who have won the popularity contest, are generally not any better speakers than anyone else, not talking about my specific niche, and not talking about their own niche intelligibly enough for an outsider. Just a 20 minute torture extended into one hour and paid for by the unfortunate masses in their registration fees.
Here's the budget from a recent conference I attended, surprisingly published in the conference program. Woohoo for transparency! What surprises me are the absolutely lunatic catering costs (14%): the catering was abysmally bad, just coffee and water in the breaks, and a conference reception with almost nothing served. (And true to US conferences, the hotel was ludicrously expensive with no breakfast included, unlike in Europe.) Definitely not worth the $71 USD that 14% of the $510 registration fee is (for minisymposium organisers--even more for regular participants). Also a lot of paying into SIAM's bureaucracy. The invited speaker costs are 8.5%, so quite a bit, but less than I expected. They filmed this conference to be distributed online, and I guess that is a lot of the 13.5% AV cost (SIAM did not even provide computers for the talks, session organisers had to bring their own)--in my opinion a total waste of participant money.