A lathe can be in poor condition and still be considered in working condition with worn ways and chipped teeth. That model was a British made pro grade lathe. If it comes with no, some or lots of tooling will affect the price and desirability. 3 and 4 jaw chuck? Quick change tool-post or the old lantern style? The area you live in also affects price. This is a total wild guess, but that lathe, in good condition, in my area, with 2 chucks and some tooling would probably sell quickly listed between $2000 and $3000. Above that mark, it would probably sit.
Are you able to post photos?