well, for things like orange sticks etc, I use ebay as they are cheap, some products I use my local wholesale then other stuffs like glitters gems I will shop around, magpie do nice glitter, but then I have bought those cheapy ones off ebay and they are no different than some of the more expensive glitters and they are fine not chunky.
But for polish I use InkLondon, and IBD I can get IBD from my wholesale which is really handy,
I use isopropyl alcohol for removing the sticky layer, but I buy it in 1ltr bottles off ebay, very cheap.