when you consider that a surley long haul trucker goes for under $1000 US complete and is A WAY BETTER bike FUNCTIONALLY speaking. It seems damn high.

Some might argue this but let me start.

Pros of LHT:
Mad tire clearance for bigger tires = better loose surface handling
Surley is double butted 4130 with oversized TT and 1 and 1/8" headtube which = more rigidity and the abaility to easily swap stems and put the bars higher without needing a to buy the one and only stem that could do this on the 720, a nitto technomic. This also means you can run oversized bars on the LHT and ergo bar are harder to fit onto quill stems... larger diamter bars are better for big guys who want a more solid front end, and are running a bar bag.
I know from experience that the surly is more stable than the old skinny tubed lugged frame and this is VERY IMPORTANT when touring loaded.

Personally if you are actually serious about touring buying a vintage 720 for that price is absurd.

On another note if you are buying the 720 to set yourself apart with a unique and cool older frame and only want to commute with relatively light loads or do some light multi day touring then that is different all together. Still from a value point of view it doesn't make a lot of sense.