I'm in the same boat with the ask first option, but I know that ruins the surprise. Any idea what type of binoculars or range finder he has? What type of hunting style does he do? Backpacking, day hunting, mountains? Here is the reason I would prefer someone to just give me some money or gift card. I need to upgrade my spotting scope, new tripod and head, hunting pack, could always use more arrows and broadheads, sleeping bag, cooking equipment, and some new camo. All of these will meet or exceed your budget fairly quickly at today's prices. If your husband has a list like this, I'm sure there is a certain order he would like them fulfilled as well, but maybe that's just me.
Have you thought about looking into getting him a tag for another state? Many of those will be at or above your price range, but if he is anything like me, I'd rather hunt with the stuff I have than buy gear and not get to hunt. Good Luck!