A high-priced Tektronix RM504
This is one of the (potentially) higher-priced Tek 504s I've seen (it is an RM504) and undoubtedly was NASA property, but it is not a flight item:
A fellow space collector has put his Apollo computer up for sale in this auction. It will likely go for a LOT of money. This is the only Apollo computer that has successfully been run so many years after it was built. It comes with a replica DSKY so you can run code on it (it does not have the core rope memory modules - it does have Raytheon test connectors presumably so Raytheon could run tests on different software versions without having different core ropes made.