That's a SB9A, pre-WW2. The racing stripes on the headstock give it away. Properly lubed, these never wear out.
This one shows very little cleaning, some rust and not great maintenance (or any lube). It has also been used extensively for wood turning: not terrible, but it will need a complete teardown and rebuild to work really well.
A perfect, pristine one should go for around $1700-2000. This one is worth just south of 700$ -- IF -- it has the 4 jaw chuck also. Without the 4 jaw chuck, I'd pay 600$ tops. If I was in a generous mood.
I agree with
@Johnwa - these are ruggedly built, well designed machines. Far better than the current 7X28/30 lathes of today. The problem with this one is lack of maintenance, and likely play in the headstock bushings due to lack of oiling. [Headstock bushing in this lathe take serious skill to properly replace. everything else is easily fixed.]