Well mine is 2007 sahara, completly stock.. Bought it this last june... 8300 miles,,, it was on the lot for 28, but i got them down to 24k, and was able to get them to switch the rims n tires off a rubicon.... ... Assuming your not paying for the rims n other mods, you should be in the 18-21k range...
Although i have a soft top,, the hard top is usually a bit more, plus, mine is a sahara, maby that will counter the cost of the hard top...
I purchased a 2007 Sahara six-speed with 20,500 miles a year ago for $22K. It is a CPO Jeep from a Jeep Dealer. It is a 2-door with both tops, tow package (4.10 gears), 18"s, sat radio. Just a data point for you.
2007 Sahara 2-door, 6-speed
Steel Blue Metallic
Mine has 35's. that one looks like 33's. those are 18 in rims because that is the smallest you can get in rockstars. And 18in rims look better on 35's imo.
I paid 16,000 for my jeep stock with 45k miles. Wheels, Tires, and lift costed me about 4 grand.
How does one tell whether a particular lift will be right for 33/35?
Ask them what the heck is under there and tell us.
If they have no idea, look at the shocks, tell us what they are.
Look on top of the springs and see if there are pucks.
Look at the rear trackbar and see if there's any sort of modifying bracket; is it welded/gusseted, bolted?
Look at the front control arms; stock or aftermarket?
Same for swaybar links at both ends.
Take a tape measure and give us the distance from dead-center of the headlight to the ground; we can tell you how much lift there is but can't tell you the nitty-gritties of it. Unless you throw in a bunch of photos...
If the history isn't written down and stuffed in the glovebox (what I'd do for a new owner if I traded at a dealer) or the old owner can't give you details, I'd move on, personally.