Are you wanting to just draw deer in for the camera or do you also want to help with feeding them and makeing them healthy.
For the camera go with the white salt, if you want to help make them healthy go with a mineral mix and you will still get photos as the mix has salt. Me and two of my buddies go in togather every year and buy the stuff mix it up and split it among us. I have good photos of deer coming into it and you only have to freash it up every 6 months. We send around $ 10.00 each for the stuff we mix and it last all year and we all put out three or more sites.
Good Hunting.