Quoting with Standard vs. Average Cost

We are having an issue with Quoting. I will try to outline a scenerio.

Customer Calls and request a quote for an assembly. The Engineer
determines what materials are needed creates the Method and pulls that
into the Quote. We have 2 of the parts in stock that have an average
cost of 1.00. The vendor sends us a 10 samples at zero cost.

Now the average cost is .166 cents each. Now if we create a quote for
a different assembly that uses this material or create a new quote for
this assembly it creates problems with quoting.

When the new quote is created it and the Engineer pulls in the method
it pull in the cost at .166 per piece rather than the actual cost of
1.00 per piece.