About the only cheap way (in cost and time) is to book some Jetstar flights in Asia, either ex-SIN or Japan. You could get 4 QF sectors that way in a day for less than the cost of a single BA flight in Europe, but of course have to get to Asia first
. Not sure that 2200 SC lifetime is much of an investment, long way from getting lifetime status (40 years for you to LTG if you only earn silver each year
).