$5K for a quality rebuild isn't that outrageous, considering today's parts and labor costs. Of course, you could always learn to do it yourself, and save a little on labor. I built my first engine in 1958, and a couple of thousand of them later, I've learned to avoid cheapskates like a case or poison ivy! They'd find a reason to gripe and moan if I GAVE them the job! My shop has over $50K worth of equipment in it, and I'm pretty frugal about buying new stuff. One of my cylinder boring machines was manufactured during WW II. I just spent $3500.00 on a USED line hone mandrel.
Jerry