We have products that we sell custom cut-to-length inches and need to calculate sale price by the product list price times the attribute value, ex 120.5 inches, times the quantity. The cut-to-length inches can be any value between 1-240 in increments of inch, 1/2 inch, 1/4 inch etc. - too many to possibly list as separate values with a Value Price Extra. 

For example, customer selects product Test Profile and then enters the exact length they would like the Test Profile cut and then enters the quantity of this specific length Test Profile. The list price of the Test Profile is .275625 uom Inch. If the customer wants the Test Profile cut to 100 inches and a quantity of 10 of these the price would populate as $275.65. (.275625 x length of 100 inches x quantity of 10).