Originally Posted by FBinNY

Yes, if the OP spends more he'll get a "better" bike, but the improvement won't make difference for his purposes -- now. His problem isn't the bike, it's his engine, and things that are fit/position related. A better bike should hold up better, which is important, but for now he has something that rolls and will help him bring his weight down. Putting off replacing it as long as this one rolls, means he might be shopping a replacement bike, when his weight is less of a concern. Plus by then he'll have a better sense of what he really wants.

By analogy, do you buy an infant a nice pair of Nike's when he just starting to learn to walk?