David Weaver gave a good answer so I'll elaborate on price. The range of prices for diamond paste vary widely, from the Norton water-based at 3.79 to 5.59 per gram in a five-gram syringe to DMT Dia-Paste at a whopping 6.95 per gram in a two-gram syringe from woodworking vendors to very cheap from lapidary suppliers. Where some may promote advantages in their more expensive brands, I cannot discern or appreciate any differences that would make a difference to me—not for sharpening woodworking tools. Now I'm not saying the higher prices are unfair, only that branded products are often higher in cost to the vendor than unbranded and perhaps well-known manufacturers are less inclined to offer the economies in recent industrial diamond production abroad.
Because 5 grams of diamond paste will last for a long time, some will certainly amortize and rationalize the cost for the high-priced spread, especially if already placing an order with a woodworking supplier for other items, and while this may get you tighter crystal size grading, slightly higher diamond concentration and purchasing convenience, I've never encountered problems with other vendors offering far cheaper products and I'm fairly demanding as most of my diamond use is for gem faceting, carving and polishing where a single outlier can set one back.
Considering the price difference between woodworking vendors versus lapidary sellers can range from 6.95 per gram down to 80˘ per gram respectively, and even lower direct from Asia with free shipping, I'll avoid the high-end as it really doesn't make a difference for sharpening tools in a woodworking shop. Yes, I will pay more for friable monocrystalline paste and highest-grade polycrystalline paste where needed but not for chisels and planes. If one has deep pockets and were to explore diamonds in the search for the very best edge, I'd suggest the aforementioned polycrystalline to be the most promising place to start.
If you want to know the differences between monocrystalline and polycrystalline diamond, this promotional literature will explain. By the way, the vendor, Pace Technologies, sells both.