I'm thinking of buying a super cheap lightweight umbrella stroller and could use some advice.

I already own two strollers (Maclaren Techno XT and BOB Revolution) which I hardly ever use anymore because my son (21 months old) enjoys walking a lot. He doesn't mind being in the stroller, but I like to let him run around and tire himself out (especially when we're at places safe from cars, like the zoo or a park) and really only end up using the stroller after he exhausts himself and needs to nap.

My car broke a few months ago and I decided not to replace it right now because I live in the city and can get around fine without one. However, I've realized that both of these strollers (even the Maclaren) are too much of a pain for me to want to take them with me on the bus and are also a pain to bring to the zoo/park because it's difficult to schlep the empty stroller and hold my walking toddler's hand at the same time.

My ideal stroller would be absolutely no frills, super lightweight, and fold up small enough that I could attach it to a camping backpack and walk around hands free. Does such a thing exist? I don't really care about the frills like recline, storage baskets, etc and am thinking that maybe I need to be looking at a super cheap stroller like this $17 Cosco Stroller to meet my needs. Am I crazy to think that I'd be better off with a cheapo generic umbrella stroller rather than my top of the line MacLaren which I never use?