I bought a red wine kit yesterday, made with Spanish Grape Juice concentrate, will make me about 21 liters of wine, I suppose that's about 5 US gallons. I decided to mix in some extra sugar and black currant juice from the garden for flavour and strength. I'll get it up to about 15% abv, according to instructions. Because of added sugar the fermentation should last 10 days instead of five. It started bubbling. Probably needs about a month in bottle after that to become drinkable...
The kit was about $30, wish me luck!