$300 is a very good price. Ask if he can send you some good pictures of the brown marble, inside and out. You're looking for damage, rust, etc. Dust and grime are cleanable. If all looks good, and you are in the market for a good table, you will not regret making the drive for this one.
P.S. In my experience, getting good pictures from many CL sellers is surprisingly difficult. It's almost hard to take a bad picture these days with a cell phone, yet a lot of people still do it.