About two years ago I was in exactly your situation. I picked up about Four diferrent condensors over a one year period that I scored, each time for around 100. My first choice would be a AKG C1000s, if you look on Ebay you may be able to score one for around 100 bucks I got mine for 120. Next Would be the MXL 603s I have seen these around that price on ebay as well. Lastly is a mic that I love on Upright bass. If you go on ebay and search for an Apex 430 There's a place in florida that sells them brand new, with a 25' cable for $109, this one is a large condensor with a great off-axis sound which is great when you're doing ensemble stuff where the mic is needed for more than a couple instruments. Oh wait one more is the Shure B.G 9.1 it is a small diaphragm condensor that has the Same capsule as the SM81(around 350 bucks) the only diffenrce is it dosn't have the -10, -20db pad, as well as it doesn't have the three postion bass roll off. But it sounds really good and I saw a bunch on Ebay for 100 dollars. Look on ebay with the smart search put in Condesor mic and set your price range I'm sure you can find something. Goood Luck!
Remember some times to make a right you need to make three lefts!!