Main bearings aren’t very expensive. The main bearings on my 90+ y.o. Saw were getting noisy ( my fault. I thought they were sealed bearings and it turns out they weren’t. I was fooled in that there were no Zerk fittings installed to grease them ).
I went to a bearing dealer and plunked one on the counter. Five minutes later I had four bearings for $28. While I was at it I added the grease fittings and regrease once a year.