It is important to call it a Marshall Peerless, not just a Marshall, because Marshall sold other models. The bed is stamped Peerless on one end and Marshall on the other. Lots of these lathes were sold soon after WWII when ex-soldiers went to watch schools to learn a trade at government expense. Lots of the lathes never got used after the owner dropped out of school, so some Peerless lathes turn up in really nice condition. Others have the chrome plating in bad shape and lots of rust on the bed. Condition affects price, of course. This one looks OK in the pictures.
The lathe and motor might sell for $200. The box of collets might sell for $125 and I have seen Waller gravers sell for $25 to $50, depending on whether the three cutters are there and still long enough to use. So, about $350 total.
Take the headstock and tailstock off the bed and verify that the three serial numbers match. These lathes were hand fitted at the factory, so odd numbered parts may not fit correctly.
Larry