We have entered the pricing on the IN-B form. When we enter the Items on a PO (PO-A) no pricing information comes up with the part information.
 
What are we missing?
 
Also is there a way to call up parts, in PO-A, using the vendor part numbers?

There is no place to enter pricing in IN-B.  The Base Price as entered in SO-Q-A is a selling price to customers, not your vendor's price to you.
 
You can enter vendor specific pricing with quantity breaks (if applicable) in PO-H.  If no vendor prices are entered in PO-H, then the system will always use Last Cost as displayed in IN-A which can be entered or changed in IN-K.
 
If you enter Vendor part numbers in IN-B or PO-K, then you can look up by them if you choose Alternates as the search key in the Inventory lookup.