Flycams are hit or miss. I got a Flycam Nano a while back for a small camcorder, and the first one wouldn't stay balanced when you rotated it. The ebay seller shipped me a new one that was slightly different (bearings and some other small parts) for free, and problems were fixed.
I did a search to see how much the DSLR version would cost, and came across this version instead:
http://www.thecinecity.com/eshop/product.php?productid=35 (more of a Merlin Steadicam design, so there should be less stress on your wrist). $99, you pay for what you get (probably problematic bearings or a very difficult thing to balance).
If you plan on upgrading at some point down the road, really consider if having a cheap stabilizer for your shots between now and when you get a better one will be worth the $99+S&H.
The Flycam Nano DSLR one (like a glidecam) is $190 (I know, above your price range), but will likely be better. How much better? Good enough? It's hard to say.
If you have the time, resources, and are interested in DIY work then try to make yourself one. Designing one takes things a little further, so I'd suggest sticking with an already existing design that you can find online. It's rare that you'll get a finished product that will be better than one you can buy for the time you spent working on it (say your time is worth $16/hr, do you think you could build a better one in less than 10 hours? You might as well buy one if not, unless you go DIY for other reasons)
