OP: to this date, Nathan states that his Shivs in 3V are his toughest knives! I think that is the cinder block stabbing demo which you were referring to. He never made any Shivs in his newly tweaked proprietary HT protocol know as D3V (D stands for Delta) but he did make a few batches with Latrobe's A2 steel prior to making them with CPM-3V. Nathan announced the retirement of that pattern a couple or so years ago, but he did make a few thereafter and then took a total of 6 of them to the Blade Show 2017. I am not sure as to whether he will be making or taking any to Blade 2018, but his 2017 Blade table prices were in the low - mid $300's depending on with or w/o sheath. That said, Nathan just announced today that his prices will be raised all across the board as he goes forward. You may visit his subforum to read his detailed explanation.
If it is a Shiv which you seek, the chances of finding one at the originally marked prices are now slim to none, depending on the availability of them in the upcoming Blade Show. On the secondary market, the Shivs tend to go for 100% or even more markup these days. About a year and half ago, Nathan started doing preorder sales for his newer knife patterns (no Shivs and no Utility Fighters), despite the practice being against his own core principles because of all the potential pitfalls and the headaches which such practices have inflicted others with. That said, he does offer preorders from time to time to cater to those who really want to own his patterns although currently his preorder books are closed. The preorder practice has slightly curbed the rampant flipping practices if people are prepared to wait their preordered turn. Note that full upfront payment is required and the wait period can take up to 6 months or more (sometimes less) depending on where one falls in that preorder list. Nathan very seldom runs concurrent preorders and he usually may contemplate starting another one due to demand as he's about done fulfilling his prior preorder list. In other words, he's very, very conservative with this approach.
I have read some other good names and makers on here, if none of the above should work for you. It's great to have some more good choices if 3V steel fixed blades are your thing.