Best to get the serial # for the machine, as that way you can know for sure what options it has. Being called "Tiara II" I am thinking it is the 2nd version.
You really need to know what features this machine offers, and what other possibilities are out there, whether HQ or Tiara. Online you can get the spec info for the current models, to identify what features are important to you, whether it be this machine or another one you come across.
Have you given one a test drive either at a dealer or at your friends' homes? Not wanting to discourage you, but you really do need to find out if it is for you. Ask your friends what features theirs have, and what they wish they had, and what would be a deal breaker should a machine not have it. They should be able you
And of course, the importance of comparing prices. An old not-out-of-the-box machine may or may not be a great deal. Also, keep in mind warranty (or not, when it would be 2nd hand) and who would be servicing your machine once you have it.
Good Luck!