Yeah, that leatherZ kit is money. $245 for spacesaver (T125/80-17) plus $60 for fitment kit (RE spacer and longer lugs). Ridiculous
I think purchasing a single wheel & tire was an excellent choice. Like the OP said it's not like you carry the spare everywhere. Only when you feel the need for it.
Might sound crazy but nothing says you can't pick a real nice wheel like a BBS or VOLK for a spare