Nah, airmiles are a scam really. Someone on here (can't remember who - sorry) did some calculations and will probable come on and show you exactly this "worth". In my opinion, keep the airmiles and use them for upgrades only.
Not even sure that always works. Just compared a flight + upgrade to club europe vs. direct purchase of club europe at BA. The costs? £558 + 20K miles for the former and £549 for the latter. Same flights, same days.
