A kitten from the rescue costs $90. For that you receive a kitten who has been:
    Spayed/Neutered ($50-$200)
    Microchipped ($50)
    Vaccinated ($15)
    Dewormed ($15)
    Tested for FeLV/FIV ($40)
Plus you get a free visit to South Mesa Vet Hospital for a checkup.
If you had to do all that for a "free" kitten it would cost you between $200-$320!
Adult cats are an even better deal! For $70 you receive a kitty who has been:
    Spayed/Neutered ($150-$200)
    Microchipped ($50)
    Vaccinated for FVRCP/FeLV/RV ($45)
    Dewormed ($15)
    Possibly had dental work ($300+)
Plus you get a free visit to South Mesa Vet Hospital for a checkup.
Not bad... $230-$350 or more worth of care for $70!