I run 2 Wright Sentars and put about 250hrs a year on each. Each year I buy a new 25hp 61" and trade the 2 year old one with about 500hrs. I first started this because the Sentar 1's were nightmares. Now I have Sentar II's and they don't have the maintenance problems the older models did. If I can buy new for $8800 and sell for $5800 that's $3000 for 500hrs or $6 per hr of use.