Dilemma of charging money from tutors and students

If you are not very fond of reading, skip to Decisions I am battling with now

I started tutorindia.net (father of teacheron.com) as a social project while working as a call center employee. I never thought it would become this big and I would need to take bigger servers, hire developers and consultants to keep it running.

Since profit was not the motive, everything was open to everybody. People could share information, contact students and teachers directly.  I even started to get emails saying thank you for the great job I was doing.

That was all good until I started to face following problems on the website:

Problems in the old system

1. Tutors and students started getting spammed by bots and marketers
2. Other tutoring websites who don't care about privacy started calling tutors - even I got calls to become one of their tutors.
3. Some tutors made multiple accounts (at times more than 10), thus stealing the chance of others.
4. Complaints from both tutors and students regarding many problems with the software.
5. Just not good enough search - so even though tutors were available on the website, students couldn't find them.

These are just five of the endless problems I faced.

The core problem was time. I didn't have any. I was, by now, working in an IT company as a software tester. So I left the job to work on the website full-time and started to take independent students that came on the website.

I don't want to do it anymore. 

I want to work full time in making this website the best website in the world for you. It takes money, time, and a lot of commitment to do that.

I am already committed so that is covered. My wife, Gagan, took care of my time by taking on most of the workload. 

Money is still an issue.

So I thought since I get so many people thanking me for the great work I have done, they would be happy to happy to fund the project. 

So I put a donate button on the website - not even a single donation. I am not sure why I was surprised. 

Decisions I am battling with now

In the new version of teacheron.com, I decided to reward people for being honest and just give more opportunities to those who are willing to pay.

So, you get enough coins to get contact details of two students. As your coins drop, so does your ranking. This way, everybody gets a fair chance.

I pegged the value of each student at Rs 500 i.e. what the tutors will pay for each student they agree to exchange contact details with. Since most teachers charge anywhere from Rs 300 - Rs 500 per hour and a student may be worth thousands, even hundred thousands, of rupees (INR) I thought Rs 500 to be a very reasonable amount. 

However, I have been getting emails that it's too expensive and we shouldn't be charging so much for this. 

Please suggest a solution or even just your opinion on the whole issue so I can keep developing this website while being fair to students and tutors. Please let me know in the comments.