Is there a minimum amount you must buy? Can someone purchase a gram, for instance?

Can buy 1g if you want. You can buy a .5 pre rolled.

There is a limit of one oz total, meaning you can get different types of product but only a oz combined so you can get flower concentrate and edibles and preroll all together.

I got a few pre rolls yesterday and two single grams

Yes you can buy just a gram ,even have pre roll j's

Yes you can purchase grams