Decent beginner bike between $300-$500?

[Eden]

I'm going to disagree here a bit..... an extremely cheap big box store road bike may actually worse than the vintage beater the OP is riding.

Problems with the $250 Schwinn (and any other big box bike)

-It will be very, very heavy - possibly even heavier than the OP's current bike

-It will come in extremely limited sizes - perhaps even only one....

-The components will be rock, rock bottom, difficult to adjust, easy to break, hard (if not impossible) to replace. In fact many bike shops will not work on these bikes because they represent a liability...

-They are often assembled by people with little to no training or experience. Many are assembled incorrectly.

I don't believe this type of bike would be even a small step up for the OP, nor would it have a very long useful life span if the OP does start to take a serious interest in riding. Invest some money into your current bike if it is worth it, try to find a decent used bike or save a little longer. You can get an entry level road bike in the $700-$800 range new.