Why are you going through so many routers? I am still using the same DeWalt laminate trimmers I have had for years, even have & use old Ryobi routers I have had for around 10 years. I have not smoked a single router yet. My shaft cutting router must have 20,000 shaft cuts by now & shows no sign of wear or required maintenance. I often read where people experience frequent router failure, but cannot relate. I'm wondering if it's the way they are used or what?
One thing I did somewhat recently was began running my laminate trimmers on a 90vdc variable speed converter instead of just plugging them into a socket & using whatever raw juice the power company is pushing. I began doing this so I could refine the power & accurately tune it, as well as control the speed for when I want to use routers equipped with wing cutters & such. What I realized is it tremenmdously cleaned up the power to a consistent & smooth flow so the routers run much smoother & actually seem to run faster & stronger. I wired in a plug receptacle so I can plug in any router & run it, just like plugging it into the wall but with infinitely controllable power. So far i'm loving it. The routers seem quieter, smoother, faster & best of all I can control the speed to get max RPM just before the point of vibration. My intention in the first place was to save bearing life by reducing vibration, but I got much more than that, which is good.
Anyway, my point is I can't really relate with going through routers. But I have experienced a neat way of controlling the routers & giving them refined power, which I think will extend their life beyond normal wall socket juice. You might try something similar before dumping a lot of money into expensive routers. I use $100 routers I pick up at Lowes, and have great success with them. I'm not saying at all that finer routers wouldn't be better. I'm sure they would. But I have used cheap routers with success for a long time & no failures as of yet. I also get as smooth of cuts as I have seen anywhere. Just a thought.