It must be a question of overheads.
It's very easy to say "Fender should drop the prices to the level of the American Specials" but with the much publicised financial difficulties I doubt they can afford to do it. None of us know the profit margin of a US built Precision. It doesn't just come down to the wood cost and the employee time - it's the rest. Transport, support staff, sales staff, building puchase, insurance policies (US Prices!) and probably one of the largest electricity bills on the planet outside of Apple.
Bulk item manufacturing margins can be as low as 10%. If it's anywhere near that then the simply cannot reduce the prices without either making a loss or reducing the cost and thus quality of the components.
I'm going to guess - the little differences between Mex and US models is going to disappear. So the Mex will get the graphite rods and the lightweight tuning heads etc. Effectively the American Standard will be built in Mexico.