what is the estimated cost fro 7gc front and rear seats....

Try newcelica.org or ebay

i was looking for some around where i live in tampa i used www.car-parts.com and found them anywhere from 80 to 600 for the complete set front and rear that web site is great for this kind of parts you just find what part and inter your zip and if will tell you where,how much, how far everything you need lol

do these bolt right up to 6th gen?

i dont know i think they are pretty close if not im sur eyou can just unbolt both rails and use the ones from our 6th gen i went and got leather seats so i didnt get a chance to try them got a better deal on the leather ones lol