you add will not truly increase the value of the house at resale...
When I built my own home years ago, I put hardwood floors and a custom compass rose in on the main floor instead of tile or linoleum. It cost an additional $6500 not counting my own sweat and tears putting it down, finishing it, and the blades ruined to cut the compass rose hardwoods (five colors)....
In the end, the value added for this was ZERO... flooring, is flooring at resale, and there are many houses with hardwood flooring under carpet.