According to Hoopsworld
http://www.hoopsworld.com/amnesty-claim-on-scola-prohibitive, when a player with a non-guaranteed contract is amnestied, the roster claim from an under the cap team has to be at least for the non-guaranteed amount. Scola's third year, at $11m, is only guaranteed for $1m. Any team who puts in a roster claim has to pay him 3/$30m.
If no one claims Scola, he will be available as an UFA. From what I understand, whatever the new team pays the player, it comes off the tab the old team has to pay on the amnestied contract. If Scola puts him out there for the vetmin, he's going to be coveted by every contender.
He'd be a perfect fit here in Boston. Scola is a savvy vet who can bang the midrange jumper (45%, same as KG) and is also very efficient int he paint (70%). He can rebound a bit, and is very gritty. One logival spot for him would be to San Antonio to play with his Olympic teammate Manu Ginobli.
EDIT
Eric Pincus just tweeted that he was wrong in his earlier Hoopsworld post, and after conferring with Larry Coonm that the actual minimum bid number for an under the cap team is $10m.
Scola will never hit the open market.