I had a 2001 monster 900 but didn't put a ton of miles on it. No problems, just routine maintenance- including the spendy valve adjustment. With the CF Termis it sounded awesome, but would wear me out on long rides. I ride a Buell Ulysses XT now which is more comfortable and in my opinion handles better.
I see a couple of mosters daily on my commute, so limited DD duty is not a problem. You should be able to get it for under $4K, here's one for $3500.
2000 Ducati Monster 750 Dark