I'd say the question is, if you actually owned a taf how much would you be selling it for !
I wouldn't normally comment on prices on a sale thread, but seeing as you asked...
I sold a TAF about a year ago for £6500 - I doubt prices have gone up since then. It was fully working (and had no credit dot), had it's topper and was in at least as good condition as this one, if not better.