Genericbikedude:Frankenstein bikes: final word. I kind of had a feeling that a $300 bike would be a POS, and yet, I've seen a bunch of them all over CC. Strangely never ridden by couriers.
I've had good experiences with Bikeline on Arch and the one way out near Newtown Square.
Re: Living in philly, which should maybe be a topic onto itself:
I grew up here, and moved up to NYC for a number of years. Its an incredibly bike friendly town, traffic is quite managable (compared to NYC anyway), and there are tons of good places to ride to/from.
If you want to own a home, I'm going to go out on a limb here and say that Philly, and the surrounding suburbs, are still probably better bet. A much better bet.
I find the discussion of west philly safety kind of hilarious. When I bike commute, I ride to/from Upper Darby to Center City.