How much does a blue tongued skink cost?

It really depends on the skink. The skink could cost anywhere from 30-100 dollars, just for the animal. As for the supplies, my best bet would be to look through here:

http:/www.reptileexpert.co.uk/KeepingSkinksAsPets.html

and everything they say they need, search each one on google.com/">http://www.google.com/ and that is the best way to find the total cost. I personally don't have time to do that now, but this is your best bet too.

Hope I helped!

~Reptile lover, and hamster and cat lover too :-D