I have the OEM bars and the Motech engine guards in silver. I took the bike to a local powder coating shop and was quoted $80 for everything in black (red, apparently, is more expensive). This included the sandblasting and surface prep, powder coating and oven curing.
I'm considering the powder coating solely for aesthetic reasons. In the meantime, to cover and protect the parts that got/get scratched by drops, I first used T-Rex tape but now will remove it and wrap some 550 paracord in those specific areas. I think it looks good (had done it on my Versys) and I get to carry emergency paracord without using up luggage space.
From my experience with rattle cans, even the combination of Rustoleum Industrial Primer and Industial Enamel were extremely easy to scratch off. I have even tried to put the painted parts in a painted cardboard box under the sun (to mimic a curing booth) without any improvement. on the other hand, things that I have powder coated (bicycle racks, including the trays, car rack crossbars, bicycle frames) need a hit strong enough to damage the metal underneath the paint and have not shown any sign of wear or rust after many years.