Fantastic price for a great telephoto zoom. I bought the teleconverter only because this lens had a fixed f/2.8, and that even with the teleconverter everything is weathertight makes it much easier to bring places I didn't like to bring my Canon and Tamron VC 70-300. This lens does not have the Tamron's range on APS-C, but I prefer crops from this lens to uncropped images from the Tamron.
The lens hood is a joy thanks to several tiny ball bearings, but due to unnecessarily rough handling in the field I have broken one hood already (got to see the ball bearings in person). Fortunately the hood is only about $40 to replace, which I consider reasonable compared to some other original camera parts. 25% cheaper sounds closer to what it should be, but at least it wasn't backordered.
If I thought my company needed another one I'd be on this drop.