Not quite sure about BA BMI and Virgin, but I think you can only get lounge access if you fly in Business or First (which you don't) or buying a club membership, or being a LH Senator will get you in. Most memberships cost around $300-$400 US so that might be a solution if you travel enough and want to take showers, snack, drink, etc.

I pay for my AC membership every year ($250 at my status level), and there's not a month that goes by where I'm not thanking myself for doing it. I'll tell you, the free cheese and crackers can save you a bunch of money if your always buying those $10 sandwiches in the terminals. Of course there's no replacing a good sit-down meal.

CF