Mk 3 .177
Reckon you're not too far out price wise. But you don't often see standard .177 Mk 3's offered for sale. Plenty of .22's. (I was quite happy to pay £160ish for a near mint early one recently).
But in .177. guns offered seem to be SuperTargets - or standard ones fitted with P/Hale sights to look like S/T's. Can't say I've seen a genuine S/T under £200 since I've been looking for one.
I guess the reason may be that 'back in the day' .22's were regarded as hunting gun's, & '177's as more target orientated - & a serious target shooter would go for the SuperTarget. So not that many standard .177's were sold.
I found when looking for early AirSporters, apart from the Club version, I saw far more in .22 than .177.
My 2p worth
Bru
Webley Mk3 x2, Falcon & Junior rifles, HW35x2, AirSporter x2, Gold Star, Meteors x2, Diana 25. SMK B19, Webley Senior, Premier, Hurricane x 2, Tempest, Dan Wesson 8", Crosman 3576, Legends PO8.