How many of EACH fabric would I buy? Wow. I walk in to a shop and tell the clerk I'll take a yard of everything.
I'd say your question IS a little vague. You didn't say how many different fabrics in the line or how many the shop has anyways.
If you are planning a lap size, it would help if we knew what size that is for you. Some like 'em bigger than others. 60" x 72" more or less? That would be about 3 yards if it were one piece of fabric. So, I'd figure about 4 yards total for the front. Plus 1/2 yard for binding. Plus extra cause you don't want to run out and extra of your favorites of course. Did you want a matching back. Then 4 yards for that.
Sorry, I guess I am not much help. Sure is fun spending your money though.