You cannot buy Max Revives, ever!
They are quite rare, but you can purchase something of equivalence in the Driftveil Market called a Revival Herb.
They are actually pretty cheap (only 2800 each!), and they have the same effect as a Max Revive.
The only fault about all of the herb items (in the Driftveil Market you can also purchase various other herb items similar to other types of potions such as Hyper Potions, Full-Heals, etc.) is that it "tastes bitter" which lowers the Pokemon's happiness a bit.
- 01.15.2012 5:04a