I completely understand throwing time and money into a project just to say, "I did it". But given the risks involved, and how cheap used Scuba gear can be found, I'd hit Craigslist up for a used al80, bcd, and a used reg set. Tanks can be found for 50 to 100 on a regular basis, reg sets for about the same. I'm in Oklahoma, far away from anything I would consider good diving, and equipment is always on craigslist. There are several Facebook based Scuba related marketplace sites as well.
Scuba is not hard, but it's the details that will kill you. Trained divers die far too frequently due to equipment issues or simple lapses in judgement. I'm not opposed to diving solo, but Training and experience reduces the risk there as well. There are private instructors that will certify people far cheaper than the brick and mortar shops are charging. Once you have a C-card, getting air fills is a matter of walking into your local shop, assuming there is a shop close by.
The best part is an aluminum 80 should give even a new diver at least 45 minutes of dive time at 20 feet. Get the training, scrounge up or rent a set of used gear, and my guess is you will be hooked like the rest of us. Otherwise, you have an untrained diver, using home built gear, diving solo, in a river (currents, debris, low vis, and whatever else may apply) ...yea...not much could go wrong there.
Good luck,
Jay