In reply to Levy_danny:
Is that for the product (and underlay), or fitting as well or levelling, product and fitting?
From experience, fitting can be done if you are a reasonable diy'er. However, the floor needs to be dead flat, so dont skimp on the self levelling fluid. (Concrete floors are probably not flat.) Also there are lots of tricks that a professional will just do, where as you're learning on the job and doing it for the first time. For example cutting into skirting boards so it slides underneath. Or removing then refitting skirting boards. Or putting beading down to finish the edge. You might get a better finish by removing and refitting skirting, but it could end up damaging decorating. If its in a kitchen, are you happy cutting into the kickboards or supports etc.
Carpet is a great draft excluder, so you may expose drafty voids by the walls than need filling. You can get foam beading for the expansion gap, that helps here.
I did our engineered wood floor, and regretted it. It took a long time, and I need to do it again. (The floor is not billiard table flat. Even though the pack says there is a few mill tolerance, you end up with a few bits that move as you walk on it.)
I got some grown ups in to do the kitchen. Half a day levelling, half a day fitting and it looks very good.