forgot to say.. make sure you clean your snake's enclosure with a herp safe, antibacterial cleaner, remove all the substrate, clean the bowl every day, and bump the heat up a few degrees.
I just use newspaper until the snake is better so it's easier to clean.
Cost is always a factor, but sometimes you have to spend tons of money to treat an animal. I bought a baby albino(from a member who I will graciously refrain from mentioning) last year, it was sick when I got it, 6 months later, no telling how much money later, it eventually died. Just couldn't kick the RI... it does happen, unfortunately.