Silver smithing doesn't get any higher quality than Jensen - the quality of the silver itself is as high as it gets as well. It should be completely hallmarked on the shanks.
In the vintage market there are, unfortunately, some fakes running around.
Some sets will run up to about 1k amonst the rarer vintage makes and the most complex new models.
The biggest vintage Jensen dealer in the States in right there in NYC.
http://www.jensensilver.com/jewelry/cufflinks-tiebars.html