Chicken or egg ?
If you don't beat it, you miss out Dr.T tropical and
volcano every 3 days, which gives good resources if you can beat at least level 1 and 2.
If you beat it, you miss out few thousand (limited by your storage) of stones.
In my case, I open both Hammerman 10 and 20 ASAP. The additional Gold & Wood from Dr. T makes the upgrade much faster, and it give stones as well.
XP27 HQ12 now.