Well if we were to use the formula: For a use activated item (infinite times per day)
Spell level × caster level × 2,000 gp
Then it would be:
5 x 9 (req. to cast Animal Growth) x 2,000 gp = 90,000 gp
And for 4/per day it would be:
90,000 gp / (5/4) = 72,000 gp
And for 3/per day it would be...