Like most Pokmon cards, the value of Claydol depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Fusion Strike)
I think since your deck needs a lot of mana to be working correctly you probably want some of the 'bigger' mana rocks, in your colours you don't have Green ramp, but you can try Relic of Sauron and/or Gilded Lotus, Lotus is a bit clunky at 5 mana but it entering untapped and tapping for 3 is surprisingly useful in practice, and Relic is never dead since it can also be used to draw stuff
Youll also want to keep an eye out for artifacts that have their own ETB triggers, to ensure youre getting even more value
color:blue type:legendary type:wizard With multiple terms, separated by spaces, Scryfall will find all cards that fit all conditions
1, 2000 Pokmon Neo Genesis 1st Edition set on the PSA Set Registry, says the Pokmon depicted in the artwork of this series are generally tamer than the aggressive looking Pokmon featured in the Team Rocket or Gym issues