The cycle of development for the game is as follows:

1.) Make content

2.) Get paid for said content

3.) Rinse and repeat

Content in this case happens to be prize boxes. The developers make prize boxes instead of 'real content' because we tend to do everything in our power to keep them from selling the real content that we want because selling this real content locks players out of the game and goes against the nature of being free to play. We're somewhat right to do this, but we're also killing the game off in the process.

I suggest that we meet halfway.

New Weapons-

1.) Release a unique prize box variant a few months ahead of time. Use this to test it as well as reward paying players with early content.

2.) Release the non-prize box variant... and require the old energy costs to craft it in addition to orbs.

3.) After enough money has been gleaned from this, remove the energy cost of crafting it.

This process guarantees that money is made off of the new content AND that it's "free" in the end.

New Levels-

1.) Release the new level with energy costs at the elevator, and feature it sparingly. 10 energy to play on the new level!

2.) Since no one is going to want to lose money playing these levels, ensure that they pay out enough crowns to justify 10 energy. This means about 1K cr per go... or better yet, just put a bunch of boxes on it so that players can get rarities without feeling ripped off by the 10 energy cost. Don't bother putting new levels in T1, as that's a very short portion of the game with very little payout that doesn't need further development.

3.) After the money to develop the level has been paid off, remove the 10 energy cost associated with it.

On another note

New doesn't have to be 100% brand spanking new.

A new level doesn't need a new enemy, new tile set, new plotline, and new level generator. If you took say, deconstruction zone, and changed its theme to contain slimes, made it use the tileset for compounds, and swapped mechas to devilites it would play super different and would be new. Similarly, changing up the waves on the arena level to be harder + re-releasing it would be new. There is serious money to be made on new that's mostly old, and seriously awesome game mechanics that are under utilized.