Not being from the USA, I don't know if college basketball is different, but most large sporting events will accredit freelance photographers and provide them with special access. Compared with being from a recognised media outlet, it is tougher to be accredited - often you will be asked about your experience, provide portfolio shots, be asked about the intended use of the photos (and often you'll be restricted to news use and won't be able to use them for other purposes). And you'll often have to pay a fee and you might need insurance. But you've got some very nice shots that suggest people are happy for you to be court-side. That will work in your favour.
How much to charge? Who knows? If they had contacted you saying that they wanted a photographer to cover 12 games during a tournament (which I assume went for a couple of days?), I'd say that $800 was very cheap. But then, I'm involved with a couple of sporting clubs (admittedly, non-professional) and apart from season team photos, we never use professional photographers. I doubt that there would be many clubs that will happily pay the sort of money that you'd normally expect to earn for the time involved.
At the non-elite end, another idea would be to work with tournament organisers to allow you to set up a table to sell the photos directly to the players and parents. You'd print off the "ok" photos taken (trying to get a photo of everyone) and insert them into a commemorative holder and also explain that the photos can also be purchased in different sizes, and if someone wanted them, they can get all of the tournament photos in digital format for $800. But this requires a bit of organisation and usually other helpers. Alternatively (and possibly far easier), you'd work with the tournament organisers to get the contact details of the players, upload the photos and provide them for sale a couple of days after the event. This is what happens with some of the running events that I take part in. For ideas on pricing, have a look at some of the websites of local marathons or www.marathon-photos.com
. Maybe you could become "footballphotos.com" and "basketballphotos.com" and even get other photographers around the world to upload their photos to your site and you'd pay them a percentage of each photo sold.