OP stated that the objective is to fly in the end of 2012 or in 2013. You have at least 6 months before the inventory even starts loading for end of 2012, so at this point it is pure speculation if you can find seats or cannot find seats. You should start actively tracking seat availability in December of 2012.
BA does give you 50% bonus from MR, so it maybe a good way to bolster your account between now and July 31st.
Best,
PedroNY