I'm guessing around 10 hours labor...just a wild guess. I did a head gasket on an 88 Sunbird 4cy and even though everything went very smoothly, it still took me total of 10 hours from start to finish...I don't think a mechanic could have done it much faster than that...but who knows.
I've heard of head gasket replacements as cheap as $500 and as much as $2000 ($2000 is a total bull s#$% price on any car). But this is probably the range you can expect if you pay someone. Pretty sad when all the parts cost around $50
Don't forget to factor in the cost of resurfacing...assuming there is warpage...could make it more pricy