Didn't want to hijack John's thread, but thought some might be interested in this.
5HP Baldor motor - $400
Hypro 2300 triplex ceramic piston pump - $300
Lovejoy coupler between them, covered with a 3D printed shield
General Pump ZK1 unloader valve - $100
Magnetic starter - $100
Pressure gauge, over-pressure pop off, inlet filter, etc
All bolted to a piece of 1/4" steel with wheels on the back
40' hose on a Sampson hose reel
MTM gun, all connectors stainless
2500psi, 3GPM, can run up to 160F hot water
Aside from the stupidly-expensive hose reel, I think I have <$1k in it
Just press the green button to go, press red button to stop - no gas, no pull starting, no fumes
Sits in my garage and never moves - I have an extension hose long enough to get to the back of the house