Whoa! A pump is dirt cheap compared to the risks of getting hurt.
6 years ago, doing step/decoction mashes, I got a hernia from lifting my 15 gallon, 60-80lb mash kettle a few times on and off my induction burner. Now that was only a 4" lift (or drop) each time onto (or off) my induction burner which was placed onto of a 14" (low) bench. The kettle would wait on that bench, right next to the burner, until the next heating step. So that's not even a bad lifting height.
I immediately stopped doing that.
I now mash in a converted cooler, placed on a 12" low bench. Vorlauf/lauter into a 3.5 gallon bucket. Collected runnings, about 2-3 gallons at a time get lifted and poured gently into the kettle, which sits on an induction plate on my countertop. No more really heavy lifting!
I could pump it to the kettle instead, which I sometimes do, when I'm in a fancy brewing mood.
I can still do step mashes by heating the mash directly in my kettle. I then use my cooler mash tun for lautering. I just scoop the mash carefully into that cooler using a 1 gallon, long handled pot. There are some drips, yup.
I now have 2 induction plates I can use side by side, so it adds more options in step mashing and performing decoctions, with no heavy lifting. Yup, brewing away.