am i being ripped off from a FORD dealer or not ?

[EvilHorace]

Maybe I missed it if already mentioned but I work at a dealership as a lead mastertech and if that happened to one of our customers, the dealership would eat the labor for the first attempt to fix it (headgaskets only) as you shouldn't have to pay double labor (or 2 sets of gaskets) just because the tech mis-diagnosed the real problem (even if it's not directly his fault per-se, didn't see cracks/whatever).
Try talking directly to the service manager/director in a calm, reasonable manner (not coming across as angry/threatening) and see if he'll agree to knock your bill down covering the cost of the initial work.