@HaasStudent - Please tell more about your situation/operation. Is this machine to be used in an educational environment (the basis of the Student in the nickname)? Is this a garage machine shop? A full blow production shop? A hobby shop?
I am always curious when people classify themselves as machinist and then seem to have no clue as to tool/machine costs. $400 per tool holder seems a reasonable price to me. If this price is not doable for you, what would the cost be for you to machine your own tool holders?
A new machine should have come with a fairly good selection of tool holders. A used machine is usually sold "as is" and it is up to the buyer to take care of anything that is missing or needed in addition to what is there. You probably got a "good deal" because things were missing.