Originally posted by Khoff2 I guess I misunderstood " use a fast shutter, nail the focus, and fix everything else in photoshop".
My guess is ignore exposure to a point. If you are shooting raw fixing exposure issues shouldn't be a problem as long as they are not too severe (I'm very new to dealing with raw and am still learning but even I managed to fix exposure).
Just a couple of thoughts. If you are shooting an indoor match, shouldn't lighting be reasonably constant? if you got an M lens for now (much cheaper), I would think you could set exposure (just takes the press of a button), then take a few sample shots, fine tune the exposure a bit, and shoot the rest of the night at those settings. Exposure should be close enough it can be easily fixed in post processing.
As far as ebay, one of the sharpest lenses I own out of maybe 60 lenses is a ricoh 50mm 2.0 that cost about 7$ shipped on ebay. You might not find such a deal on such short notice, but don't discount chinon, sears, ricoh and others, especially with 50mm primes. there are tons of them out there (M not A though) in the 1.7-2.0 range that can easily be had for under 25$ (possibly a lot under if you get lucky). RioRico could probably give you more recommendations as he has a billion primes while I only have a few (I favor zooms).
I would personally get an M 50mm 1.7-2.0 for now since you need it right away, bring the kit lens as a backup since you are used to it (maybe shoot with both), and have a little more patience getting further lenses (if you want bargains anyway). Most fast lenses tend to be expensive (new, used, old, recent or otherwise). I wanted a fast zoom and didn't feel like paying 100$ plus at the time. got a kalamar that was broken (only cheap one I know with any merit), got outbid on several trying to get another (not going to pay 50-80$ as its too close to what a much better one costs). 4 months later, I scored a camera with winder etc., the kalimar, and another lens for 28$. The other lens had fungus so 10$ refund, so 18$ for the kalimar in good condition. RioRico's strategy of bid often, bid low and expect to loose most works great.