If they are pre-owned at 400 - 450, they are way over priced, relative to 550.00 brand new from Magepan, in your choice of grill covers. Save up the extra 100 and buy new. I have a pair I bought new and set them up every so often and listen to them. They are worth more to keep them than to sell them used. The pre-owned market price should be in the neighborhood of 275-300.
Just my opinion though...
Just my opinion though...