There is no "Magic Set" - And the days of sets going to 4-5x MSRP, personally, I think - are more or less gone (minus the very occasional outlier before I get responses with the couple of sets that have done it). I think the POTC/Harry Potter wave was the end of that era in Brickvesting. There are lots of options, lots more folks in the game - I think 3x MSRP is going to be more or less "peak". I think even "hot" sets that aren't widely held like Town Hall and Super Star Destroyer will plateau around this mark.
If your goal is to maximize your investing dollar, there's no reason to spend $150 on a set that retailed for $130. I imagine the ceiling for this set being $300, and probably $250-$270 may be more realistic which seems to be where a lot of sets in the last 3-4 years at this price point settle. You'd still make money of course, but percentage wise - not nearly as much.
If your goal is to have a couple of a unique/rare set, well then go nuts. But if your goal is to get the most bang for your buck, as others have mentioned - Look for ISDs/At-Ats/Cantinas and even Imperial Hotels at small discounts or near MSRP as opposed to paying OVER MSRP for a set who probably that has already reached halfway to its max. Heck, I'd rather grab another Death Star at MSRP than 2 LM's at above.
LM is obviously doing fine, but I think you wanted to be in at around $100-$110 max. As others have pointed out, maybe people especially in Europe snagged these at 50% off.