Definitely. Our group is small and two of us host almost all our games at our homes so the to of us do all the work. That said, it is not unusual for other players to bring along a new game that neither of us do.
Ever since I started (with one exception) I have bought, built and painted all of the combatants, terrain etc that is needed for our games with our children, grandchildren and club members. This means I have a huge and varied collection. I now have several collections that I would not otherwise have had - zombies, survivors, Martians, assorted aliens, the Hobbit etc.
Now our eldest son is keen on 28mm WW2 (Bolt Action and Chain of Command) and he buys the models, I build paint and store them just no while he is deployed on operational tours.