JVM - maybe get a "girls" bike? I know where you are, and if theft is as big a problem as I hear from my family folks there, a "girl" bike might fare better. It's not as macho to have one, and they don't re-sell well.

GT made some pretty decent girl mtb, I almost bought one for $125 at my used bike shop. Some of the older Trek girl mtb are nice, too. Of course, if you can find a girlie road bike that would be even better for your 8 mile commute.

Then, if your nice girl frame doesn't get stolen for a while and seems safe from theives, you can start subtly upgrading components....

Let me know if you want me to scope out Recycled Cycles for you. Right now they have very few used bikes in stock because they are selling like hotcakes. But, y'know, any excuse to go hang out at my LBS!