The silver PL-600 is a decent table for someone on a budget, but it's really considered no more than that. It would probably go for around $100.00 on eBay if it had a usable cartridge, the cable wasn't repaired, it ran as it should and there wasn't much in the way of visible wear or scratches. I'd want to replace the cables myself... That would bring the price down considerably, as would any signs of wear or any mechanical problem. But, the AT15XE is a fantastic cartridge sought after by many audiophiles and they're not that easy to come by. That would bring the price up some... Maybe an additional $50.00 to over $100.00 if there are low hours on the stylus and someone believes it. The rubber suspension on a stylus can harden due to exposure to air over the years though, causing severe tracking problems and record damage. So, the stylus isn't necessarily good even if there are low hours on the tip.
You're probably looking at a value of over $100.00 mainly because of the cartridge, but likely less than $200.00, depending on your skill as a salesman and how many other old Pioneers are on the market at the time... how bad somebody wants an AT15XE at the time... I'd definitely include the AT15XE in the title for any ad or auction.
I'd probably be willing to buy the cartridge for $100.00.