Mixed feelings on this. Yes, it could very well have been purchased as a close-out at Home Depot when the orange model moved in and may have been 1/2 price or less. But, there is no reason for the seller to pass this discount on to anyone. The discounted purchase price is irrelevant
A few months ago, someone was asking about a used orange model. As usual, the 1/2 price arguments were made(by me as well) and as I recall the woodnetter lost the purchase and several woodnetters mentioned that "good" jointers were hard to find and prices were higher than you may usually think.
So, if the jointer drought is now over and 1/2 pricing is normal again then $200 may be OK for a used model in good shape but pretty far off target for a an unwarranted but new in the box unit.
If the OP has other real options or is willing to play the waiting game then passing on this at greater than $325 would be reasonable otherwise it may be a regrettable miss.
I certainly would NOT go $400 but I would consider $325. I would also ask the seller to open the box, assemble the machine, and demonstrate its functionality first.
I would never buy a pig-in-a-poke from a stranger. The box must be opened before I would even consider it at $50.