Granted, I have a degree in electrical engineering, but certification was not part of that degree. I got the certification at a night school, IIRC it took 2 months with about ~5 hours per week in effort. If you don't have experience with electronics it would obviously take a bit more effort, but it's totally doable.
How many weekends does it typically take before you're ready to sell?
This sounds like something I'd do even if it just barely covered costs (including a reasonable per-hour time cost).
And a good property manager should take away 95% of the hassle.
I've heard of 5% of 1/12th of the projected sale price, which seems more realistic.
There are lots of other things to consider but it’s a great quick rule of thumb.