i don't know how big your babies are... but here is a way to make a lil sock shirt!
How To Make A Dog Sweater From A Sock | Itchmo: News For Dogs & Cats
wal mart and target have cute clothes for inexpensive!
check the dollar section(when you first walk in) at target.. they have cute stuff for like $2 bucks!
also, big lots!
good luck!!