Oh, poor little things
They are both very, very sickly looking. Its difficult to know what to say re: buying the other. I know it'd break my heart not to, but by buying them, would the irresponsible keeper just get more and abuse those? Urgh. Would the current keeper take well to some advice? Perhaps you could print out the pages from Caudata.org, or link him/her through?
Knowing me i'd end up rescuing them!
What are you feeding him? Earthworms are the best possible food, and goodness knows that little guy needs all the nutrition he can get!
Re: the stones, better safe than sorry, you'd be alarmed what they can swallow by accident. The rule is they must be much bigger than lotls head. Sand or a bare tank bottom is better, and easier to keep clean (crud gets in between stones and can affect your water quality). Is your new fella pooping ok? He could already have swallowed a lot of stones...
Re: wild type, wilds have the gold sparkly bits, sometimes around the eyes, melanoids have no sparkles, just the stealth, ninja look
Good luck helping the little guy get well, please keep us posted how he's doing.