Toxapex is not found in the wild. Catch Mareanie on Lost Islands or Appendix:Brick Bronze Walkthrough/Chapter 24, then raise it to level 38 for Toxapex.
Decently High Demand/Usage
Prices from the trade team's value list, in val; a Bottlecap is worth 6 val. The list prices the copies people trade for, so a plain one may not be listed.
Speed at level 100: slowest with 0 IV, 0 EVs and a −Speed nature; fastest with 31 IV, 252 EVs and a +Speed nature.