Anyone know why lamb is so cheap now? $4 to $4.50 pound for boneless leg

[KurtNYC]

23. I found parts of this (somewhat confusingly written) article very informative

New Zealand/Australian Lamb are quite small in size, with whole legs coming in at around 5 to 6 pounds. According to Mark Pastore, it's a matter of both genetics and feed. Lambs from Down Under are smaller to begin with, and they spend their entire time grazing on grass, giving them a more intensely gamy flavor that some people can find off-putting. They also tend to be lower in fat, making them a bit harder to cook properly
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American Lamb, on the other hand, are larger, fattier, and sweeter in flavor. Most American lamb are fed on grass most of their lives which gets supplemented with grain for the last 30 days before slaughter. The lamb at LaFrieda comes from Mennonite farms in Colorado that finish their lamb on a combination of grain, honey, alfalfa, wheat, and flaked corn.
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Bone-in leg of lamb like the one above comes in two forms: shank end, and sirloin end (occasionally, you'll find a massive one for sale with both the shank and the sirloin still attached). The shank end lamb legs start at just above the lamb's ankle and go to midway through the calf bone, while the sirloin-end legs start at the hip and stop at around the knee.

I prefer the sirloin end because the meat is fattier, more tender, and the cut is more evenly shaped, making it easier to cook evenly. On the other hand, the shank end tends to have slightly more flavorful meat. Its tapering shape is desirable for some cooks, who like being able to offer both medium-rare meat from the thick upper part and well-done meat from the thin lower part all off of the same roast.

http://www.seriouseats.com/2011/04/how-to-cook-lamb-for-easter-nz-australian-or-american-roasting-times-oven-seasoning-bones-carving.html