So I've got my new bike picked out and on its way and I need some shoes and pedals. I've got the shoes picked out but I'm torn between two pedals. I tried the shoes at one of my LBS and have the size right so I can order online. Pedals I'm not sure about. I'm torn between these.

http://www.amazon.com/Shimano-PD-670...7935030&sr=8-1

http://www.amazon.com/Shimano-PD-570...8198147&sr=1-4

I know ultegra is the better version but for a relative beginner is it going to make that much difference. I'll be a on a trek 1.5 and I've seen the ultegra's at my shop. As far as I can the tell the 105's are really no different. Is this just clever marketing my shimano to get more money out of people?