Worth getting the BA AMEX credit card. The blue one has no annual fee and you'll earn an Avios per pound spent (minimum - sometimes more). Even if you only use it once a year for the sake of getting a handful of Avios, they'll transfer over in any given amount (i.e. 3, 7, 24, whatever; not only when upwards of 500/1000 like some earning systems such as some surveys) in the month following allocation.