Mine hits about 5000-5100 rpm. My lab job cost me about $300. I took him a stock 26P and he took out some cup and pitched the prop up one pitch to make it almost a 27P. My boat ran 79 when it was me and a buddy with no gear and about 10-15 gallons of fuel I am guessing.
The prop calcs are pretty good estimates for how fast you should be going, but they dont take into consideration the hull type, weight, x dimension etc. So, like I said, it is an estimate.