How many hours to do Valve Guide Seals?

[Skyline]

How many hours should it take a pro-mechanic to do the valve guide seals on a 4.8 N62, using the AGA kit? This is assuming he's done the job several times and knows the job.

I am contemplating having a good neighborhood independent do the job for me, and he's never done this job before. I want to agree on a proper number of hours to be billed before he starts; I don't want to pay for his learning curve, nor would he expect that.

I'm guessing around 15 hours...what do you folks think?