@gabirdman – If you are running out already, it is probably too late to continue in MYD unless you can buy telepods as @amslimfordy points out or buy characters, which is expensive.
Or, if you are not in a hurry, you can sit and do Carbonite melts religiously for a while, until you restock. But you won’t get the really good characters that way.
There are two other radical approaches that I know of.
It is too late to use this first strategy, but you can learn a lot from it about what you could have done to avoid this, and how you can behave differently in the future. @daboid is a master at stretching coins and characters out as long as possible, and has made numerous posts explaining that strategy.
On the other hand, like @daboid, I made a decision to never spend real money on characters, and, similarly, to never run out of them. But I started the game without the benefit of help from ABN, and had made too many mistakes by the end of Return of the Clones. Sound familiar?
My radical strategy was to start over, from the beginning. All you need to do is set up a different Rovio account. If you have gone through all the levels it is surprisingly easy and fast to start over and catch up. You don’t have to 3 star anything in order to earn enough coin to keep going, and you can always come back for the “3 star everything in this chapter” coins later.The benefits of a do-over include recognizing what you did wrong the first time, patting yourself on the back for what you have learned, and having a much better idea about what characters that you need to buy and hoard.
But this is a very SW2 focused approach. I did take a look at the other Angry Birds games and do not like them nearly as much as this one.
Good luck to you! I would be interested in what you choose to do.