It's very poor if BA don't cough up for the lounge, bearing in mind the £300 premium mentioned earlier for the Club ticket. The lounge costs around £20 for adults and under £10 for children. I'm sure BA would get it for considerably less than that.
I use the airport about twice a month and very rarely use the lounge. (Only if substantial delays). I sometimes take a posh pic-nic and sit outside as someone else suggested. I buy a bottle of wine from duty free and drink that. (I know that's not allowed but the airport doesn't seem to care).