A wedding is not the time to look ungenerous. Examine your budget and be realistic about what you can provide. Three hundred people in black tie requires unlimited champagne and hor d'ouevres, a three course seated dinner and an extravagant band, not a DJ, and probably some sort of surprise entertainment, as well. If you can't afford this, or don't wish to entertain in this fashion, you are by no means alone. Few people can and will have this kind of wedding. So, don't ask your guests to get in black tie unless you are going to provide a black tie entertainment.
Eleven thirty weddings are popular in England, why not here? This unusual time will set your wedding apart. You can choose to have a sit down luncheon from 12 to 40 people or a buffet for 200. Four thirty used to be the most popular call time for a wedding. When Dean Manigault got married her mother hit the mat when Dean Manigault wanted to start the ceremony at six o'clock. Maris asserted that 4:30 was the chicest of all times and was not to be moved from this point. Eleven thirty, four thirty, noon, whatever time you choose, just be sure the entertainment you provide is as lavish as your budget allows. The Deans have been to barbecue and beer receptions that were way more fun than the time Dean Manigault flew to Capetown and was presented with a bill at the end of the rehearsal dinner!! The single most shocking event of her long life!
If your budget solution is to have a cash bar for your wedding then you have not come up with a suitable solution. The Deans were never more shocked than when they heard about this trend. You don't have to invite everyone you went to school with or ever met. Less guests can frequently mean more fun. Especially if none have to reach for their wallets!