Amass Oozes X, where X is number of creature types among creatures on the battlefield. Don't count changelings. That would be ridiculous. (To amass Oozes X, put X + 1/+ 1 counters on an Army you control. It's also an Ooze. If you don't control an Army, create a 0/0 black Ooze Army creature token first.)
NM-Mint - $18.40
Lightly Played - $16.60
Moderately Played - $14.70
Heavily Played - $12.90
Damaged - $9.20
NM-Mint Non English - $18.40
Lightly Played Non English - $16.60
Moderately Played Non English - $14.70
Heavily Played Non English - $12.90
Damaged Non English - $9.20