Is it improper to have a cash bar at our reception, even if we will have around 400 people and don't have the money to provide for everyone?
While it is often necessary to find ways to cut costs, a cash bar is never a good choice. When you have a wedding, you're inviting people to a party, and they shouldn't have to pay for anything while they're there. Yes, it's true that when you have a bash in your apartment and invite all your pals, you say "BYOB," but it's not quite the same at a formal event. Better to try and save money on the alcohol itself -- and don't worry, there are a number of ways to do that.
Consider having a "limited" bar. Serve only soda, beer, and wine or have a champagne toast. Some couples have a signature wedding cocktail, which cuts down on the different liquors and ingredients you'll be purchasing. Also, confirm whether you have to buy your alcohol from the place where the wedding reception will be. You may have signed a contract that says so, but if not, it's generally much cheaper to buy your own liquor, wholesale -- you can get more for your money, and get what you want.
See More: Most Asked Wedding Questions , Wedding Reception Ideas , Wedding Receptions