Often around here the "Want Ad" - a little newsprint cheap publication that you can find in grocery stores, convenience stores, etc. has that sort of thing for sale second-hand. Do you have anything like that in your area? I'd also check with veterinarians in your area - they probably know people with birds or who used to have birds that could make a recommendation.

Welcome to Pet Talk, by the way, and congratulations on rescuing both birdies and changing their unhappy circumstances!