What is your real-life Beta "stars spent to DS won" ratio ?
You seem to be doing slightly better than 10:1 (ie 10 attempts: 1 DS won).
...
It would seem imperative to limit yourself to 1 DS per day (unless you win 2 from the double payout).
Considering that each piece may only appear twice (and some only once) ... it might be quite costly to get multiple copies
(esp if you leave the unwrapping for late in the season).
I haven't kept count of the Stars I spent.
Being beta, I also spent diamonds on one occassion that I probably would not on live: I went through about 120 Stars and ended on a double, given the odds, I bought some more Stars and it paid off, givimg me 2 Moose Meadows.
My Sugar Baker's Booth came from winning a competition on beta, so I shouldn't have counted that at all.
Roughly 360 + 290 + however many I bought = 700ish Stars used to get 7 buildings when concentrating only on the Winter Set and playing smartish.
You are right: once (IF) you've won a DS for a day, then the smart thing to do is stop, unless perhaps you only have 3 or 4 tiles left unturned. Hence the reason why the cost of buildings is so much higher than the typical cost of winning one, though attempting to win at least gives other stuff along the way.
I've also just realised that my calculations on odds have ignored that one of the presents is some stars, effectively making the initial odds 1/17 not 1/18.