The timer is a minor deal. A little bit of a bigger deal if you got a different size heater, but not much. On some makes there is a check valve and a few other things, but it’s still a quick job.
The timer is connected to the hose bib drain, or is it on top of the hot line? I have had both, no way either requires more than 1/2 hour to remove and replace, even if it were soldered in, less if it was originally installed with proper unions as needed.
If it was soldered in, he cuts it in one or two places max. and re-installs it with $2 solder fittings ,or $6 unions, or both(up to two pieces). Maybe he needs a few inches of copper pipe. So you would have 1/2 hour plus a few bucks in parts(before insane mark-up).
