I bought a Tubus Cargo for 26" wheels for a 700C LHT on touringstore.com recommendations and it fit perfectly. I've since had a couple of lower bars and struts added to it for a lower installation so I can ride with milk crate on top and panniers on the bottom. It now sits on a 26" wheel LHT.

Regarding the rest of your queries on prices and such for a 10yr old bike I don't think there's enough first person information on the condition of the bike to render a judgement and your intentions are kind of all over the map what you want to do. If you want to buy a bike why the heck are you considering reselling it? Also the lack of clarity of standover height, 3" or 1.5" kind of tells me providing feedback is of limited use with such unclear perceptions on your part.