A collection that includes a Base Set Charizard (in any variant), a Shining Charizard, a Gold Star Charizard, a Charizard LV.X, a Charizard EX from the XY era, a Charizard GX, a Charizard VMAX, and a modern Charizard EX SIR tells a complete visual story of how the TCG has changed over 25-plus years, and it represents a focused, achievable goal that still carries significant prestige and value
It shouldnt be too hard to get your full value out of Cryogen Relic, ideally by sacrificing it for some kind of other ability, but having its own buyout option is a nice backup plan for that
Lastly, my attention is drawn to some exceptionally powerful creatures in Karametra's column
If a Pokmon your child likes is a Basic Pokmon, or if you want to include them as a lucky find, it might be okay to include about 1 or 2 of them in the 10 cards