How much does an complete set of the Radioshack Pro-64 costs?

Today i have been cleaning up some stuff that was kinda buried for decades, and i found a radioshack pro-64 in the middle of it. It is almost brand new, with box, manual and everything, and is even working! I searched for the price but i could'nt find a single one for sale, so if someone could help me i would be really glad! If someone wants pics of it, be welcome to ask!

TL;DR: How much does it costs?