How To Use Stonks:

https://pokeheroes.com/stonks?i=shiny%20stone
https://pokeheroes.com/stonks?p=combee
https://pokeheroes.com/stonks?p=shiny%20metang
https://pokeheroes.com/stonks?p=mega-able%20abra
https://pokeheroes.com/stonks?p=togepi%20(retro)
https://pokeheroes.com/stonks?p=shiny%20ponyta%20(galarian)
https://pokeheroes.com/stonks?p=shiny%20rattata%20(alolan)
https://pokeheroes.com/stonks?p=growlithe%20(hisuian)
https://pokeheroes.com/stonks?p=shadow%20clefairy
https://pokeheroes.com/stonks?i=magearna%20egg%20voucher
https://pokeheroes.com/stonks?i=magearna%20pb%20egg%20voucher
https://pokeheroes.com/stonks?p=magearna%20(master%20ball)

Replace the name after i for item and p for Pokemon. Change the name of the Pokemon after shiny, after which mega able, retro and shadow. For Magearna Vouchers these are the only ones I've found so far and for just Magearna change which type of ball.

Some Pokemon and Items do not have a set price yet with Stonks due to market fluctuation. If you click on the very end of the blue it will give you the exact price along with the range.

I'm assuming due to fluctuation there isn't a set range for Shiny Megas but it seems if there were this would be the code:

https://pokeheroes.com/stonks?p=shiny%20mega%20gengar