Idk geez I couldn't live w/o a stroller whether 1 or 2 kids lol when washer us nice we walk almost everyday. Go to the park, use it shopping, the zoo etc. We too only have one car that is y it's great we got a double stroller before we even bought the babes infant car seat lol (we had plenty of time this was months ago) but I couldn't stand not having a stroller to take our son to the park to far to walk for him but not me or, walk across town to my mil, the library, the bank ifi would need to etc. Or simply just to get out and go walk! :-) plus xwe have zoo membership so we go a lot and def need a stroller there!
Eh, we don't have a reason for one so we bought a light weight stroller(not an umbrella stroller but a full size) it was around $80. I wanted it just in case for some reason i needed it. My SO works 40+ hours a week so that means I'll be home with no car with a toddler and a newborn. We r looking into a double stroller as well. You could look for a gently used one since your not sure if its going to be used or not.
They are good if you are going out like to the park or walking or some people use them when they go grocery shopping and know they will have a full cart. You will be surprised on how you won't want to hold your baby all the time and the carseat is heavy