Formulae and Samples

Man, I am spamming this subforum, aren't I?  I've got a question about samples/formulae and how they affect the price of commissioned items.  Let's say that Gworg the Unwise wants to commission a magic-user to craft a sword +1, twin to the one he uses, as a gift to his henchman.  A sword +1 has a base price of 5,000 gp and takes one month to craft.  With the sword as a sample it costs 2,500 gp and takes two weeks to craft.  

Which number (5k or 2.5k) do I use to determine the cost of special components and the price to base the commission off of?

IANANANA, but I'd use the first number for special components and then make the commision somewhere between them. I don't think you use less dragon blood when you've got a schematic, but it *will* take the creator less time and resources in general. 

IANANANA, but I'd use the first number for special components and then make the commision somewhere between them. I don't think you use less dragon blood when you've got a schematic, but it *will* take the creator less time and resources in general. 

So, to break it down the costs might be as follows:

5000 gp base price to make sword +1/2 because sample = 2500 gp

5000 gp in special components

It normally takes one month to craft, but with the sample will only take two weeks.  As per p. 227, if successful, the adventurer is charged an additional fee equal to 7000 gp/month *or* twice the base cost, whichever is greater.  In this case the 7000 gp is greater, so he ends up spending 2500 gp for the base cost plus 5000 gp for the special components (assuming he purchases them*) plus an additional 7000 gp, for a total price of 14,500 for the sword +1.

*I am working on the assumption that, since monster parts are a tradable commodity in this game,the client can simply purchase the special components instead of obtaining them herself.