You could pickup a BSA ultra second hand for less then £350 if your lucky, my mate sold me his (single shot) for £150 with a shitty tasco scope on and a weichrauch silencer. It's an excellent shooter and in excellent condition.
You can get them regulated to get a more consistant shot, and more shots per-fill, there a good super-light super-accurate hunting pcp. My only dislike is the MMC cocking system and low shots per fill (35 in .22).