You should consider other things besides cost when choosing between the
two. I personally feel that marble is not a good choice for anything,
so I would go with hardwood. Or if you like the "marble" look - go with
granite ($$$$)

In NJ, you can get grade 1 oak hw floor + 2 polyurethane coats and 1
sealer for $6.50-7.00 sq. ft.

Probably cheaper where you are.