The price of my Scorpions was about $1485 per tyre, including cost of balancing and fitment. I had asked for a discount and got 5% off the original price, so it came out to about $1485 or around $5900 or so (not including alignment - I did that outside after Automotive Components facked it up and made my truck pull to the left).
I was trying to hold off for the BFG's from Quikserv, but they were really expensive at $1800 or so per tyre. My main consideration though was the same as yours - I drive 95% on-road and 5% off-road, and I read great reviews of the Pirelli Scorpions. Everyone kept saying how it lasted them a long time (65,000km's and more) and they performed very well on road while keeping a decent off-road performance level. The only thing that defeated the scorpions was mud and soft-clay.
I would have gone for the Toyo Open Country, but I wasn't satisfied with the relatively quick wear-rates, although the average life of the tyres from reviews online was around 45,000km. Not too bad but perhaps by taking care of the tyre (regular alignment, rotation & balancing, etc.) it would extend the lifetime.
Here's a side-by-side comparison of my dad's Pirelli Scorpion STR vs my Pirelli Scorpion ATR


His scorpions were bought from Pricesmart in 2007, have about 50,000+ km's on them, and he doesn't drive hard at all.
Funny enough, I think his tyres would do much better in mud and soft clay than the ATR's I have, which are a more road-biased tyre.