You need to shop around as prices for Copper Sulphate varies greatly. Have a look at rural feedstock outlets, they should carry it, and may be cheaper.
Copper Sulphate comes as Blue crystals, and has Water of crystallization, and it is also available as anhydrous version which is more a whitish powder.
Both works well, but the Blue Crystals, what you buy contains water. Formula is CuSO4.5H2O. The white powder version contains little or no water. You can buy it on Ebay cheap as, when comparing it to other outlets.
Just an afterthought, if you are interested, you probably can make your own Copper Sulphate by using Old Lead Battery acid and scrap Copper wire, Copper tubing, and let it soak in the acid, in a plastic container/bucket that is OK with acid use. (use excess Copper to acid in weight). The Copper will dissolve slowly, and the acid will start to go blue, but if you have time and in no rush, it is an easy way to make your own Copper Sulphate. The best thing is, that it is free, if you have old dead car battery and scrap Copper.
Take care using battery acid, and just make sure you dont get the acid on yourself or your clothes. Wear rubber or latex gloves and eye protection against splashing.