That picture looks like the gun I owned-except for the butt stock.

When a boxlock starts getting above about $2500 in price, it's got to be a pretty special piece in my opinion. I will happily admit I'm cheap, and not a collector, just a shooter. I wouldn't pay more than that sum for just about anything boxlock, including the Tzar's Parker. That said, I fall into the camp that believes the boxlock design an improvement upon the sidelock design, and considers the market to have it backwards, a happy set of circumstances, for me. Getting the balance right on a Martin is a tough task, and is a further strike against buying one sight unseen, and for more than average cost, compared to similar, conventional guns.

If you just have to have one, they are nice little guns, if, and that is a big if, they are done right. Like a tatoo, you better like it.
Best,
Ted