Like most Pokmon cards, the value of Kabutops 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 (Legend Maker)
You can understand the basics of the rules through the playing Q&A
I think it's a deck-thinning card, and in that effect it is really strong
Rule of Law | Illustration by Scott M
My Garchomp card with its flowing design, the always-charming Psyduck, and even Tirtouga look fantastic here
Firstly, she taps for mana, and when that mana is spent on a creature, it enters with two +1/+1 counters on it - representing her literally summoning a powerful monster to the battlefield