You would probably need an Items table (tblItems) and a Parts table
(tblParts).  tblItems would have fields for ItemID (the primary key),
Description, etc.  tblParts would have PartsID (the primary key), ItemID (of
the same data type as ItemID in tblItems, or of data type Number if ItemID in
tblItems is an autonumber), price, etc.  Click Tools > Relationships, add
both tables, and drag ItemID from one table on top of ItemID in the other
table, and let go.  Click Enforce Referential Integrity.
Make a form (frmItems) based on the tblItems (or better yet, from a query
based on the Items table) and another (fsubParts) based on tblParts (or
query).  With frmItems open in Design view, drag the icon for fsubParts onto
frmItems.
I know you asked about price, but more information is needed.  The total
price of all parts for one item?  For all items?  The price of the Items
themselves?  Calculate a price based on what?  You can do all of this with
Access, but your question needs more details.