Ok, all you Saved Search Mavens out there, I'm trying to do a formula (text) field where the following custom item field is an integer value.

CASE WHEN {custitemquantity_free_ship_customer} =1 THEN 'ShipsFree' ELSE {custitemquantity_free_ship_customer} END

if I pull it by itself, it works fine, but if I try to do a Case/When statement on it, it fails as "Invalid Expression". Does anyone have any insight?

does it matter that {custitemquantity_free_ship_customer} returns an integer (in the case where it's not 1) whereas the formula is text?

That's probably it. try

ELSE TO_CHAR({custitemquantity_free_ship_customer})

after messing with it back and forth... turns out the "proper" form of this formula is

CASE WHEN ({custitemquantity_free_ship_customer} = '1') THEN 'ShipsFree' ELSE {custitemquantity_free_ship_customer} END

For whatever reason... parenthesis helped it work along with putting the value in quotes.