Sorry about that, we had lots of trouble with WebGL in Chrome under Yosemite. It did seem to clear up with a new release from Google a few days ago.
The click-drag interaction on desktop is slightly goofy. We discussed adding cursor key and clickable arrows for previous and next, but concluded that it wasn't that bad. It's super nice on touchpads and touch.
We pin the price to $100 and vary our markup depending on volume. The most dramatic landscape in Norway, Trollveggen – the image we shown on the site, gives us a markup of exactly zero. We're running this off a small cluster of colocated boxes with SSDs to handle the IO for the elevation models. So it's mostly to keep the lights on.
That said, we hadn't tested it on flatter landscapes and the models we tested with only gave us a markup of a few dollars. The markup we put on your model seems slightly greedy. We're lowering it now to a maximum of $20.