Ashley, you can try Kid to Kid there are two locations that I know about one is off of Tatum just past the PV mall and the other one is at Shea & the 101 in the pima crossings shopping center, they have all second stuff, clothes, toys, strollers, cribs etc. many times I've gone shopping there and have seen all sorts of different strollers, including the double ones.
Good luck in your search