I would think that £200 would get you a good Tau 7, which uses 12 gram cartridges; +/-33p from JSR for 80 shots. An excellent gun which can take you into the mid 90s if you have what it takes!
Some of the others, older FWBs and FAS are at least equally good if not better, but do not come up for sale so frequently.
Forget big bucks PCPs until you really know which pistol you want for ever (almost!).
Walther CP-2 Match, FAS 604 & Tau 7 target pistols, Smith & Wesson 6" & 4" co2 pistol, Crosman 1377,
Baikal IZH 53 pistol, Gamo CFX Royal,177, Umarex SA-10 CO2 pistol.