JD parts are way more expensive then average tractors- I have a 90 murray i got free back in 2006, i put a new mandrel on it back then , mowed with it till a few days ago and it needed another new mandrel and a magneto - 5 years trouble free seems pretty reliable to me - i had the spare parts already , so it was a free fix and 2 hours downtime fixing it myself.
Price some basic repair parts for a JD and see how much cash youll save.....
If you bot two tractors and keep a basic supply of maintenence parts on hand ( Oil, belts, blades, couple mandrels) youll see a whole lot more profit sooner - taking the tractor in to a shop youre looking at $40 plus( seen some up to $65) an hour plus parts.
Or just buy the JD and see....