Yeah, but those are matched sets of single TO-92 transistors, a far cry from manufacturer matched JFETs with the dies (often monolithic) in the same package and in intimate thermal contact with each other. So you're actually paying more for the making of matched sets while getting lower matching performance.
Linear systems actually do a monolithic matched pair (the LSK389 at around £4 each) with the same specified characteristics as those individual LSK170 JFETs you've linked to at 27.00 for a pair (presumably USD, the site doesn't specify). Heck, the datasheet for the LSK170 even says "For equivalent monolithic dual, see LSK389 family". The site seems to have been created to take advantage of price gouging audiophools who don't know better (and don't bother to read the datasheet).
The LSK170 is an equivalent for Toshiba's discontinued 2SK170, much loved for its very low noise (0.9 nV/sqrt(Hz) typ @ 1kHz, 2.5 nV/sqrt(Hz) @ 10 Hz) and consequently revered by audiophools who then proceed to feed it from a grossly inappropriate source impedance from a Johnson-Nyquist point of view.