I'm a world class scrounge; I try not to pay retail unless there's a good reason- such as a warranty I'm likely to need.
I paid about 20 cents on the dollar for my used chillers, and got the new one at forty percent off.
Swallow hard, buy a good, big one (twice as big as you think you'll need), wire it in properly, and you can use it to heat and cool your home and your domestic water, not just your growroom.
Don't forget to add the cost of dehuey to any AC purchase you shop for comparison, and also keep in mind that chiller operating costs are 30% lower per BTu than AC.
Those two factors make the initial bite of a quality chiller much easier to take.