E.T.
You get what you pay for. The Bob is amazing. Try looking on your local Craigslist for a used one. If you have a big weight difference (baby versus 25 pounder) then getting a really good stroller is even more important so it doesn't pull to one side while you're running. Plus, some of the cheaper ones have less cushy rides which can be a bit tough for a baby.
I bought our Bob in 2008 for $480 at REI (used the 20% off members discount) and sold it in 2011 for $350. So it really only cost me $130. Bobs have awesome resale value...