I agree, price sounds way too high. Unfortunately, these blades are a good example of how often times what something costs when new has no reflection on its used market value after a few years. I sold a very clean, excellent condition 60" #375 blade last year that I had purchased for $150 ( ebay) and sold it for $350. The #375 was designed for the 750 series tractor but is very similar to the #380. They have different mounting brackets and the #375 has an extended frame that runs to the rear end. The front ends of the plows are identical from the pivot forward. They are very heavy/ well made and designed to have extended wings bolted on to the sides of the blade if you need extra width. They are no fun to swap off/on as kennyD mentioned. It seems to me like the ones I have seen are either pretty beat up looking because they were left on the tractor all the time and subsequently used for years of pushing snow, dirt and gravel too...which is fine, they'll hold up to it. Or they look really nice because as Kenny said, they were used one or two seasons then left in the corner of the garage when the owner decided it was much more simple to just use the old rear blade/sore neck method.
Summation: Great blade, very well made, hard to mount/dismount and $1150 is more or less twice what I have regularly seen them sell for on Ebay and Craigslist.