For that budget it's definitely going to be spring and you should get a decent second hand rifle but then don't forget a scope can set you back a bit as well. Don't buy cheap as you will regret it but you don't need to splash out either. A budget scope but from a well known make should be okay, hawke is a favourite and I do like Simmons myself. Personally as we'll I won't buy second hand scopes, plenty of people do but I'd just rather not as they can be broken so easily.
A bag is a bag really
Pellets again don't go for the cheapest most people spend around £10 a tin ( accupell, rws, air arms