Thoughts on whether these parts are genuine/good buy.

Apologies if this is the wrong thread, but tech_association in California is selling quads of 'USA Stock Toshiba 2SK170 LAB Tested Quad 4 matched N FETs 7-10mA' for $19 here: https://www.ebay.com/itm/256263712435

And LME49710HA mono opamps for $3.99 here: https://www.ebay.com/itm/256652413375 I'm more interested in these but there a lot of Chinese fakes around.

They have plenty of positive reviews, some confirming genuine parts, no complaints. What do you think?