I know some companies do all their drawings by hand. I've used draftspersons that can trace an existing drawing but who don't seem to understand what they are drawing. I have an inventor who wants to do his own drawings. Patent drawing appear simple. Our charges vary according to the job.
Schematics cost less, complicated machines requiring development time cost more.
Over the past 10 years, thanks to computer drawing, the cost for most patent drawings has gone down. We have no fixed turn-around time. We prefer that our clients tell us when they need the drawings. We have met same-day deadlines when necessary. We appreciate greater lead time when possible.