When is it time to let your Grizz go??

My 2002 660 has little over 6000 miles on it. I kinda like fixing little things that go wrong. In the last year the little fixes are getting more and more frequent. Starting to get a loud whining noise from the belt area. Got me thinking the main bearing is going out. Don’t know though.
I have already have the go ahead from the wife to get a new 700 Grizz. Just trying to save up to pay cash by this summer. Its not worth it to anyone but me to keep it running and I’m scared to sell it and it fall apart on whoever buys it. When I get a new one it won’t be that big of a deal when the old one is down. Just use it for a backup I guess.