This card is difficult to find in perfect shape, so the market price is a TCGplayer estimate based on a handful of sales, with LP copies maxing out at $69.99, giving some reasonable credibility to the $94.50 market price
A downside of building a Mutant cube is that, because the focus is so heavy on Evolutions, it is difficult to include the high HP, high damage EX cards of the current format
As for negotiating itself, go watch a few episodes of Pawn Stars
What's in a Pokmon booster bundle
Final tally Lands: $200 Instants: $1325 Creatures: $5077 Sorcery: $3327 Enchantments: $380 Artifacts: $7,225 Total estimated deck value if I had just kept these cards: $17,154
When compared to only other cards in the bonus sheet, Gemstone Caverns comes out ahead of the rest of them