I think that is excellent service on your LA120. I also think that you made a wise choice to get it because it has a 2-blade 42" deck instead of the 3-blade 48" deck. That smaller deck and the manual PTO are two things that will make your mower last longer. However, your initial price for that mower was probably around $1700, so your cost so far is not zero. It would be at least $17 per hour plus maintenance items. Every year you use it, the cost-per-hour will go down as you put more hours onto it. When you sell it and buy another mower, then that sales price comes off the equation and raises your ROI. If you were to get to 500 hours, you'd be in really rare territory with cost based on purchase price only being $3.20 per hour. We are all a long ways from that, but many of the sturdier JDs have 500 to 1000 hours with only routine maintenance.
Thanks for posting. It's great to see you are getting good value so far and I hope your LA120 makes that 500 hour mark.:thumbsup: