Two or three hours for a first time clutch repair is very optimistic. Three hours is doable in that time if you have the right tools and someone who has done it before. You need to jack the vehicle high enough to get the tranny out and rent a transmission jack for ease and safety
I would guess more like 4 to 5 hours, maybe even 6-8 hours if you have to make multiple trips trips to the auto parts store. Without a grease rack, it is hard to maneuver the tranny in and out in the tight fitting spaces. things like getting those 2-4 top bolts in and torquing them can take 30 minutes or more by themselves on some vehicles.
It's worth it, though.
P.S. Sorry, I missed the part about paying for someone else to do the clutch job. It normally doesn't matter how long it actually takes. They have books (for mechanics) that list the length of time that it takes to perform routine service tasks like replacing a clutch. Most shops refer to these and quote you based on these estimated times. Any competent mechanic can do most of these jobs in less time. I think that the times listed for most clutch jobs is 4-5 hours, whereas, a good mechanic can do it in 2-3 hours with a grease rack and parts in hand if there is no major resurfacing of the flywheel..