I saw it on sale and it's mildly tempting for such a low price but Shenmue 1 was one of my most tedious Platinums ever. I can appreciate that it laid the groundwork for things like the Yazuka series but man, was it a chore to play. I've heard 3's Plat is even worse...
If you thought 1 and 2 were tedious, 3 is even worse. I get they tried to keep the same feel of the old games, but they made design choices that made things even more sluggish. And this is coming from someone who replayed 1 and 2 before 3 and still enjoyed them. My biggest issue was their new "stamina" system where they basically just made your stamina and your health the same thing. And if you decided to run anywhere, your stamina would go down (to a point, not enough to kill you) and you would have to eat food to refill it. So going anywhere meant you had to sacrifice health for speed, you're forced to either walk everywhere slowly or make sure you had enough food on you or were at least near food to buy. Made the game so annoying. Not to mention they basically padded the story by making you do the same things twice, just in different locations.
I mean, if you really want to play it, $4 is a great price. I bought the base game on or near release then bought all the DLC later for super cheap, but I don't know if I'll ever go back to play any of it.