Why buy new - well, to begin with because finding what you want/need is typically much tougher for a "typical consumer" and many times when you do - sellers mistake lots of tire kickers as being a sign they can price for 95% of new and get it.
Heavy equipment and compact tractors are different markets. Something like this is overkill for someone looking to maintain 5-40 acres of personal property. Running a farming operation as your day to day job - yes, this makes sense - clearing the drive and hauling firewood - its too much. You hear alot of people say you "can never have too much tractor" - sorry, but you can at a point. Right now its hard to keep a full time operation profitable for many, and if you wanted to start from scratch - most would probably say your crazy...legacy operations have what they need in place and paid down - carrying more debt would crush most start ups.
Different markets for similar equipment can vary greatly - financing options. Again, if a pro farmer needs financing on used equipment, there are plenty of loan programs out there and banks with experience lending on these type of operations. For a buyer who walks into a local bank/credit union and says I want a 13k loan for a "lawn mower" as many of these loan officers will see it - they are going to write the loan much more carefully - sure, if you have a debt to income and high score to warrant the risk - they'll make the loan - but riskier profiles in the eyes of a bank are tough sells - new the manufacturer finance program can lump these loans into packages and secure the financing for the buyer - no different than how Harley Davidson and ATV/UTV manufacturers and RV/Boat makers have done for years. They know their markets better than anyone.
3k hours on a machine like that wouldnt scare me - its clearly built to last the demands of a full time operation. Maintained properly (as you would assume someone who relies on the machine to make their income would do and keep records of) - stuff like this can be a bargain for the right buyer. 1500 hours on a small unit from a homeowner who failed to keep things up and never changed fluids/filters or greased the machine only to polish it up when getting ready to sell - your taking on a potential nightmare.