If it were me I'd offer $25 for just the critter, and the owner could sell the tank and other stuff separately because I don't need any of it. That said, I already have another separate empty QT setup, a good herp vet, and plenty of credit on the AmEx should it be needed. So, I'm in a different place in life than you are.
Once you get to a place in life where you have more room and resources, and you become known as "that person who will take in unwanted snakes", trust me, you will have plenty of opportunities. I haven't bought a snake in years but somehow I keep ending up with more...