I have the DMT 8×3 stones, and I use every bit of the 8×3 face of them. My assessment is that you are paying more, but you are paying for quality, customer service (if required), and permanency. I’ve heard the EZE-Lap stones are good, too, and not quite as expensive.

I cringe to think about sharpening on 6×2. Just not enough “runway”. If you go this route, you can sharpen blades wider than 2″ by turning them sideways, but I think that introduces potential for uneven wear.

Sandpaper isn’t a bad route to go getting started, and in my opinion, a continued requirement. You just need to procure a good flat surface to affix the paper to.

I keep 80, 150 and 220 grit sandpaper for conditioning and shaping of newly procured tools. I rarely use my course (200 grit?) stone, but jump to my fine (350 grit) and extra fine (800 grit) stones for final maintenance and honing.

I have a Faithfull 400/1000 diamond stone and after 4 years it still works fine despite the abuse (I tend to press too hard when sharpening). It came dead flat and after the initial wear (common to all diamond plates) it shows no other signs of deterioration.

I also have a Norton India combination stone, which I use for my everyday sharpening as well, and I totally agree with @Dave Ring that it’s just as effective though a bit slower than the Faithfull. It’s narrower than the Faithfull and therefore I have to skew the wider plane irons (not an issue really) but the final surface is better polished, compared to the diamonds, and it’s easier to sharpen very narrow blades due to the continuous surface.

After the stone (no matter which one I have used) I go straight to a strop.