My ignorance is strong, too. So there.
Especially, for current purposes -- in that I've used oil stones (yes, dry), but ... like.... once in the last 20 years, and once or twice very incompetently before that! But you did not read that waterstones are best used dry. They need water. Some are "splash and go" and some need to be soaked for a while before use. But never dry. You did read (probably here) that oil stones are better used dry. I'll point you at various very wise and detailed posts BDL has made on the subject. (Really just put "BDL" and "Arkansas" in the search bar and you'll find that).
Water stones wear away over time. The abrasive works for that reason -- it comes loose from the top of the stones in small amounts. Some more than others. So the two sides of stone will wear away at different rates. Basically one argument is that they're not cost-efficient in the long run. They're two separate, smaller stones, glued together. You can only work from one side of each, they are thinner (I guess I meant that when I said "smaller"), if you use them a fair amount at all it just gets more expensive to replace than separates. And also you might find that you don't like the same brands in the two different grit sizes. So you get some advantages from separates both in terms of choosing what's "good" and in terms of replacing what you need when you need to. That's one side of the story.
The other is that if you don't yet know how committed you are to sharpening, if you don't do it a whole lot, if you don't have much cash to outlay on the front end.... well, it's a cheap way to get your feet wet. (And it's what I did, it seemed like a good way to start and just learn the basics).
Waterstones were really made for harder japanese knives. They are faster than oil stones. (Used dry, or with water, or with soap and water). But maybe not relevantly so on knives like the Sabs. I'm sure you got the Arkansas stone, dry, idea from BDL. Who knows more about sharpening carbon Sabs than ... for all practical purposes, anyone. I'm pretty sure he'll tell you the oil stones are more ideal for the carbon Sabs, though water stones will work. And then I don't know about the cheap/combo water stone, in particular, as a comparison to the oil stones.
I've sharpened a kitchen knife on oil stones once, ever, in memory, on stones that was (like the knife) purchased by my father in 1961, and treated badly. (OK, unlike water stones, they oil stones aren't going to wear away and have you sharpen in the "mud" of the dissolving stone -- they just don't work on that principle -- but they do get loaded with swarf from the blade, and need to be cleaned appropriately so they're not just completely filled in/loaded up with knife-powder. The stones I used were not maintained properly. This is all to say... it's not my thing, I've done it very little and under very poor conditions. It totally "worked" to get the knife sharper anyway, but.... I can't really speak knowledgeably about whether the edges are longer lasting or otherwise better or the sharpening experience is better or how... or if it's a matter of the oil stones actually being cheaper than a comparable quality water stones, all that.
You need to hear from BDL on this. He's got 4 different sharpening kits.... two of which are at least in the ballpark of the comparison you (and I) are trying to make here.
And I *do* have some carbon Sabs, I have sharpened them on an inexpensive combination stone, it totally worked. I learned to sharpen on that one. And on the other hand, yes it did turn out more expensive in the long run... but that was fine with me. I sort of figured out a little bit more about what stones I wanted, and I learned a bit about sharpening over that time, and I gave the (not very worn away at all) combination stone to my sister, who has a Japanese knife now.... I have no regrets about the inexpensive combination stone. (BTW, it wasn't the same one you're looking at, nor from the same vendor. But I was buying a bit blind and have no idea how they compare with what you're looking at.
Yet... circumstances were different in that I needed something for harder steeled Japanese knives as well as the Sabs, so I *needed* water stones. I'm considering buying a kit for my father, who has never touched water stones and doesn't need them for the knives he owns. And that would be oil stones, because he's more comfortable with the idea and he has knives that don't need water stones. (Even if I can't quite make it clear that he should boil the oil out of them and use them dry).
