I have no idea what they "usually" go for, but also check
Bill Jenkins of Signature Lincoln Mercury
(search Troubleshooting for his website and 800 number.. you get a CEG discount...)
and also try
Steve at Tousley Ford
(Search Troubleshooting for his 1-800 number as well, as he can usually net about 45-50% off of new OEM parts. Mention his "SVT" plan to get the discount (you don't need to own an SVT)
Ray