Wow! Great catch!!!
If I had paid just $8 for that machine, I'd have been looking over my shoulder for security guards on the way out because I would have effectively stolen it. I wouldn't have been able to leave it behind, either.
It's rare that I see a Kirby--or any vac worth having, for that matter--at a thrift shop around here and never for that cheap. Usually they're pretty broken down and overpriced for their condition so I usually just let them go. In fact, the only Kirby I've ever bought at a thrift shop was a nice Gsix, complete with its toolkit for $50. Not a steal of a deal, but not exactly a ripoff, either. At thrifts around here, I actually seem to see more classic Electrolux machines, both canisters and uprights, than I do Kirbys. The best deal I've found on one of those was a Diamond J canister with hose, wand and PN5 power nozzle for $10.