If it's a 2005 it's probably a "Vista" model. The "Landmark" was only made until 2003. In 2004 it became the Vista, and the interior was remolded. Otherwise it's basically the same dimensions on the outside, 8'4" x 7'7" x 38".
You can check the serial number on it if you wish. The "Landmark" models began with either an "S" or "SQ". The format should be something like SQ#A####. Each # equals a number. The letter after the first # designates the year it was made.
A = 1999
B = 2000
C = 2001
D = 2002
E = 2003
F = 2004
G = 2005
The fact that the dealer called it a Landmark doesn't cause me any suspicion. The model designator in the serial number for a Vista is "SS". When you have options of S, SQ, or SS, it's a very honest mistake. In fact often times when you order a cover from Hot Spring for that spa, the label on the cover will say Landmark/Grandee. The Landmark changed to become the Vista, and the Grandee is the exact same dimensions but different interior.
So Landmark & Vista are essentially synonymous, they just technically refer to different model years.
As far as the price goes, I'd ask about what is included and what is not. For instance, for the $6,000 is the dealer willing to give you an in house warranty to cover any potential problems in the future, and if so for how long.
