Another for the Tau7
Superbly accurate, Good trigger when set up properly, spares are ridiculously cheap and readily available and they are a nicely balanced pistol,
Earlier CO2 are also good but some are put off by bulk fill (although his is very easy) Spares are getting scarcer for some models however,
Baikal 46m- great pistol but hard to get at a good price now and spares becoming an issue,
Gamo compact - for £100 used an accurate pistol that will certainly get you started,
For £450 you'll not find many PCP's of match quality (but for £250 you'll find a very nice example of a Tau7 that will serve you well and still be worth the same if you later decide to go PCP cos you got hooked ,
Nige