The seller read the wrong tag. Understandable. It happens a lot.
52-866 is listed as a Stand for the 37-195 T2, 37-275X jointers according to Delta's J-2I Parts illustration.
So the stand fits under either of those two jointers.
Both are Asian import jointers although sometimes the stands are USA-made.
Condition is everything. Rusty and beat up with dull knives, not such a bargain. Pristine with sharp knives, still a little strong unless you're desperate.
Not sure if age matters, but many of the older models were designed with rebuilding or replacing parts in mind. While they are no longer made, the more popular brands often have parts availability better than some of the more recent tools.
edit: Agree with Bob—that’s a bit expensive given the availability of used 6” jointers.
I'm guessing something from the 1960s or 1970s would be good to search for like these 6" Powermatic Model 50s from the 1970s. Often they can be found cheap because the seller is too lazy or incompetent to rebuild them. A rebuild generally encompasses taking apart, cleaning the ways, replacing the bearings and knives and you're good for another 30-40 years.
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Keep your eye on Facebook Market place and Craigs list. Should be able to find one for a good bit less. I saw one just last weekend on FB, an old Jet, for $150. Needed a new on/off switch, it was direct wired. Plug it in and its on. But was a good deal if it worked. It was gone same day. I see them in the $200-300 range regularly.