PCP's are great, very accurate and easy to shoot but more expensive to get started.
Another advantage is many are multi shot like these 2.
AirArms S410
Rapid Super7
A cheap second hand PCP might be a nightmare for someone starting out and i would only buy one from a known source and somewhere you could take it back to sort out any problems.
PCP's also require charging gear which puts the price up even more.
Forget any CO2 guns for hunting, it can be done but it's not for a beginner.
Fun for plinking but not serious shooting
Good solid second hand springer like a Weihrauch could be had for £150 and will last forever provided you do a little maintenance (5 second rub over with an oily rag before you put it away).
Model choice is down to what works best for you, spend time in a gun shop trying as many as you can and then if you think they are too expensive chance the BBS.
Classic HW77 on left and TB90 on right, not much to choose between them in terms of power and accuracy but they balance very differently so while both guns in theory shoot the same you one might well shoot one better because you can handle it better.
AirArms and Theoben springers are good but can be expensive
Only thing about buying from a local gun shop is the after sales service, especially if it's your first gun.
Saving a few pounds at the start can be expensive in the long run.