Subforms in Creator-Lookup Price

Subforms in Creator-Lookup Price

I've got a modular called Price List with items and prices. Ive got another module called Estimates with a subform that looks up that Price List. I am trying to get the "Price" to auto-enter based on the Lookup field of the item name. Anyone know how to do this? 

I then want to group the pricing of the items based on each Stage as a sub-total. Anyone know how I can do that?