You both have good cases; you just have different preferences and priorities. Why can’t you compromise and try shopping together for awhile and spending, say, $650 a month on your groceries (splitting the difference)? This would make it more of a joint/team effort rather than a competition or argument between you two.
There may also be ways for you to prioritize which food “luxury” purchases are worth the most to you, while saving money your husband’s way on things that don’t matter as much to you. Then you’ll both get what you really want, while understanding and appreciating the other’s perspective more. You’ll enjoy doing the shopping and eating together more too!