Long-term Rancher owner here! I purchased my Honda Rancher 350 the first year of production - in 2000. It has served me faithfully for 22 years! The newer one's, as you know, have a higher displacement engine (mine is only 329cc), are now fuel-injected rather than utilizing a carburetor, and water-cooled instead of air-cooled. My machine always fires right up and runs, and runs, and runs! We also have a newer 420 Honda Rancher with independent rear suspension and all the other, more modern, bells and whistles (this is my wife's machine, of course!).
One additional purchase I made for my 2000 Rancher involved a trailer from Bass Pro Shops - Yutrax HC1500 ATV Trailer (
https://www.basspro.com/shop/en/yutrax-hc1500-atv-trailer?hvarAID=shopping_googleproductextensions&ds_e=GOOGLE&ds_c=BPS%7CShopping%7CSmart%7CAutoATV%7CGeneral%7C NAud%7CTopPerf%7CNMT&gclid=EAIaIQobChMI1bjqz9OR-QIVmonICh2jHghVEAQYBCABEgKkUPD_BwE&gclsrc=aw.ds). I purchased it on a good sale and use the heck out of that trailer. I did have to purchase a different neck (is that the name?) so that the trailer could attach to the ball on my Rancher. Northern Tool also carries some very capable trailers for these as well (the four-wheeled versions should be very rugged - if your budget permits).