The county shelters in my area are pretty cheap.
Prince William County
Dog Adoption Fee: $55 (includes $20 adoption fee & $35 towards spay/neuter fee)
Cat Adoption Fee: $45 (includes $20 adoption fee & $25 towards spay/neuter fee)
City of Manassas
Dog, Adoption Fee $20
Dog, Spay / Neuter Fee $100
Cat, Adoption Fee $20
Cat, Spay / Neuter Fee $80
Animals already spayed or neutered $20
Fauquier SPCA
Dog Adoption Fee: $115
Includes:
The cost to have the dog spayed/neutered (must be done before the animal can go home)
A heartworm test
The first distemper vaccination, Bordetella and worming
Microchipping and rabies vaccination.
CAT Adoption Fee: $95
Includes:
The cost to have the cat spayed/neutered (must be done before the animal can go home)
A Felv/FIV test
The first distemper vaccination, Bordetella and worming
Microchipping and rabies vaccination.
Fairfax County
There is a $20 adoption fee for dogs, cats and rabbits, but if the dog or cat is not altered, there is an additional fee to get it altered before adoption: F-cats $55; M-cats $30; M/F dogs $65
Loudoun County
Here is a link, because there are too many to list, but basically their fees are $100+, more for unaltered animals, and less for senior animals:
http://www.loudoun.gov/Default.aspx?tabid=1179#fees