They aren't all expensive.

I have a fisher price one from Target. They have changed the branding and it is now hipod or something like that. I think it was about $300 for the capsule and maybe $180 for the stroller. Although they have them on sale regularly and I think I got both for about $400.

Target also sell a steelcraft one. I think it is steelcraft cruiser. Like the strider, but not as expensive. I think that one was a bit more expensive.

I found it such an excellent system. Especially after a friend told me about walking around the shopping centre for an hour because her baby was asleep in the pram. I could easily move bub from car to stroller to home.