If you have space, buy a couple plants and you'll have an endless supply. They spread and grow like wildfire to the point of needing to be cut back every couple years.
I bought some dried berries years ago for syrup and the taste was putrid. After that experience I now pick the berries and freeze till I'm ready. I've been wanting to make wine too but only have about 5 gallons of frozen berries which still isn't enough to make a 5-gal bucket of wine.