Yes, I remember prices like that. The first two air rifles I bought with my own money were from The Mart in Lowestoft (?), in about 1980 or 81 I got a Webley Hawk MkIII (advertised as a MkII, so I was a bit disappointed when the MkIII turned up) for IIRC £27 or £29, and a BSA Mercury S for £69.
In 1983 I bought a BSA Centenial for the almost unheard of sum of £230 and I remember my dad saying at the time "what tha spendin' all that money on a bloody air rifle for? Tha must be daft"
The South of England has 2 good things, the M1 and the A1. Both will take you to Yorkshire.