Yes, I do strongly disagree with the harbor freight comment.

In my previous life I purchased a lot of forklifts over the years, both used and new. The only way to buy a used forklift is if you knew the previous owner and type of work it was doing. For example never buy a used forklift that's been used in a foundry, regardless of hours and price... The safe way to go is to buy new and take care of it. Resale value will be good and in the end cost of ownership on a new machine may be less than buying a trashed used one with lots of problems. I suspect used skid steers/track loaders have a lot in common with used forklifts.

Judging a piece of equipment by demoing a used machine with worn track sprockets and a loose boom is just not realistic. The machine above sounds like it's been used in a frac sand mine.

My JCB 300T gets greased. One rear boom pivot zerk is inside the engine compartment and my dealer mechanic pointed that out.  Having a boom that moves that much side to side I would stay away from that machine. Every other pivot is probably shot also. Have the track tension cylinders ever been greased? Probably not leaving a loose track.

In addition to the side door, the engine compartment on the JCB is much better laid out than other track loaders I looked at. The ISO controls take some getting used to but like anything else there is a learning curve.  There are a dizzying number of control buttons and switches on the electro hydraulic hand levers but I've figured out the ones that I use.