sometimes people have a budget and they try to get the best fit.....
Thanks to all of you for your thoughts and comments. I'd love to buy they 7K$+ mower and I know you'll get value for money, but I'd better be realistic.
Based on the comments I think the ZT with the 180 hours for 3K$ or less (still have some negotiation space) is probably the best deal I can get for the job.
Forgot to mention that it probably is for the next 4 years, so with the 180 hours on the clock, 4 years of 100 hours to go, I should be fine....
Still the questions remains; anything particular I need to look at when buying the used TZ? Anybody aware of particular week spots I need to focus on? Thanks in advance for your advice!