wood flooring

Roughly $8 psf and up for very high-quality 3"-wide, 3/8"-3/4" thick with 1/4" hardwood top-layer, engineered and unfinished, PLUS $4 psf for installation PLUS $4 psf for finishing PLUS up to $1 psf for delivery. Expect to add $2 psf to move from 3"-wide to 4"-wide, and another $2-3 psf to move from 4"-wide to $5-inch wide. (Beyond 5"-wide is unusual, and price may actually decline owing to unpopularity.)

Also depends, what kind of floor are you looking for, solid aok or engineered? You can get a nice engineered floor for $7-$8 sq ft. and if you have a concrete subfloor it should cost $4.00 to install more if you need to level the subfloor or if you need a new subfloor.

If you get 3/4 oak that should be much less but the chances are that you need a subfloor

What is on your floor now? Do oyu know what is under it? Who is going to remove the existing floor?

concrete subfloor and i'll let the installer remove it...

Obviously the demo and removal is more money. The cost will vary depending on the size of the apartment. He will also be removing the base molding so you need to purchase that along with someone installing it. Wood floor installers are not the best molding installers, make sure they use glue (Liquid nails) and finishing nails, they should also fill the nail holes and joings with wood filler, sand them and then paint.

So you have

Demo and removal: figure $1.00 -$2.00 sq ft
Purchase wood (prefinished, glue down) $8.00 (you could get for as low as $5.00 I wouldnt go any less)
Install wood; $4-$5 if the sub floor doesnt need a lot of prep
Purchase molding: 1.50 linear ft
Install molding: $10-$15 linear foot