CRB pg. 224:
A spell amp always has an item level equal to three times the
level of the spell it duplicates (treat as a 2nd-level item for spell
amps with 0-level spells), and a caster level equal to its item
CRB pg. 222 / Table 7-27:
Item Level 10
I have checked aonsrd.com as well to confirm that those numbers were also the same.
Are the numbers indicated in Table 7-27 for 3rd-Level amps an exception to the rule like 0th-Level amps?
If not, then assuming that the item/caster level should be 9, what would be the appropriate cost of that item?