They sound like lucifuga, which commonly show up in people's basements in certain parts of the country.
As for price, since they are technically "wild" collected animals, they are probably illegal to sell and buy. Depending on which state you live in, they may be illegal to keep as well (OH, TN...not illegal to keep, but illegal to collect, off the top of my head). Check into the laws in your state and the state where they are coming from.
As for keeping them in general, they make awesome captives are very interesting and hardy animals to keep as long as you meet their temperature requirements. If it is legal where you live, I'd highly recommend it. Cave salamanders are typically VERY abundant in regions with appropriate limestone geology. There is a serious lack of appreciation for our native salamander species, and if only people who crawl into caves to find them are exposed to these species, it is highly unlikely the situation will improve in the future. Breeding them is a challenge, but not impossible. I can share what I know about it with you if you'd like.
Good luck!
Tim