Looks like it's probably oak to me....those big 5 legged extension tables usually were oak.
I have one I cut down for a coffee table and put several coats of poly varnish (not water based) and it's been used and abused for 30 years and looks...not like new LOL but let's say un damaged.
No idea what to pay.... can't see a lot from your pictures.....

Thank you, Linda. The owner's measurements were off by 16 inches, so the table is too big for me. What about this table? Is it Revival from the 1940s? How do I know whether it's really hardwood and not veneer?

Here is a link that might be useful: another farm table?

The second table is veneer. You can see a repeating cathedral pattern on the top. Also the joints on the ogee edge do not match up with the top seams.

Veneer is not necessarily evil. I took a veneering class from a guy that makes $50,000 - 100,000 veneered tables. he started off the class by saying, "Veneer is used on the very best and the very worst of furniture."

For a table, veneer creates a top that's less likely to have defects, less likely to warp. less likely to crack, and less likely to have wood movement issues.

The problem with veneer is that you can't "abuse" it as much, right? i need a table where dents, nicks, scratches, etc. are part of the patina,a nd I don't see that with a veneer. Or am I wrong?

nosoccermom I agree with you I prefer a solid top that can eaily be refinished and can take more abuse. It is very difficult and risky to refinish a veneer top.