I probably spent half my time on those rear inner lines. With the bleeding 3 hours seems reasonable to me. If you use a good independent shop that charges by the hour and has done the job a few times, they might do it in less.
I hate paying 2-3 times in labor what the parts cost. To me, the more DIY that I do, the more money I have for mods. I have not paid a shop in years for anything other than an alignment.