If you're using low pressure, you will be using more $$$ for chemicals. If you're using chlorine, you'll spend appx $1/gal. Chems shot through an injector are pulled @ 5 to 1, @ 3gpm, so you'll be using appx ONE gallon per minute of CHEMICAL. Plus the labor to do the clean/rinse. $50 per hour is ok if it's one person I suppose.... I don't know how much "extra detail" can be involved, you should just be applying a chemical to everything and rinsing it all off at low pressure... If done right, there is NO "extra detail". If it's "more than" what a normal complex would involve, you can add that in. I do $85/hr for hourly rates (although prices are actually about $150/hr for normal labor) when I'm in the field. So if I know I'm using $5 in chems, 1 hour (let's say, oh, $1000000.00) labor, plus set up/ break down time, I know I should ATLEAST charge $10000010. Or however.
Sometimes it's ok to take a loss though, eating is important too! lol