Not that I know what the price would be, but I put the Type "S" suspension on my car this last weekend, the fronts are fairly easy to do, took about 20 minutes each. The backs are a little bit tougher as you have to remove the ilink bar that connects to the sway bar, remove the rear cover garnish, so maybe a little more involved at about 30 minutes - total to remove old and put new ones on about 1 hour 40 minutes, lets say 2 hours with coffee breaks.
The additional time for yours is you have to remove the old coils with a spring compressor and then install the new coils, there is a diagrahm in the NSX manual about how to line the bottom mounting point to the top coil cover which looks very interesting to get lined up, being careful to align properly without the need to over stress the mounting points if you dont get them perfect and there is litlle room for error. If you have the right tools I cant see this adding more than 15 minutes to each spring - so another hour.
I think the approxiamete time would be 3 hours for a rookie. :biggrin:
6 hours seems extreme - I would call Chris at Science of Speed and order the Type "S" or "R" complete kit, it maybe cheaper.
2 hours also seems like a lot for alignment adjusting -
Just my 2 cents. Thanks and good luck