Yes, 119DU are all you need, you can use the rest as you want, either add healing auras at hint 3 and 5 or place gas, proxy/etheral, inferno over at hint 4 and 5(help with spider, djinns, ogres)

Pre-Wave 1: start as you fastest char(I use aura monk) to collect mana. Build everything but minions, total mana remaining at the end of the wave should be 0. Should have 20 sec to change char.(change to upgrader(low dmg weapon+genie), I use jester)

Wave 1: Upgrade hint 4 buff beams, drop mana at forge, move to hint 5 upgrade buff beam and kill any enemies remaining, go back to forge as wave ends.

Pre-Wave 2: You want some casting on your summoner because you don't want to stay as summoner during wave. Change to summoner, build minions(use mana you have on you and mana you dropped earlier). You should have 5-10 sec depending on your building speed to change char. Change to upgrader again. The core build is done.

Wave 2: Go to hint 2 and upgrade both buff beams, then, move to hint 4 and upgrade everything. (Upgrade priority should be hint 4, 2, 3, 5, and leave South West crystal for last.

Pre-Wave 3: If you want to add any more defences, add now(DO NOT ADD APPRENTICE TOWERS). Else proceed with upgrading rest of the defences until boss wave.

Boss wave: Change to a dps char(monk with a dps pet would be optimal for stability), add your builder summoner, builder monk and a random char(if you have one with good resists and a cat, put that char in). When wave starts, move your chars to hint 2. Dps around the map.

Boss Countdown: Run around the map and repair auras and traps if needed(you will be busy during boss). Then go to hint 2 before countdown ends.

Boss Walkthrough: Start at hint 2 dpsing the snowman, after he's dead, wait for the 2nd snowman to arrive(in the meantime, dps the annoying squire). When you kill the 2nd snowman, get rid of the squire(leave the other 3 kids there) and move to hint 3. Go behind the mage there and dps the snowman. after you kill him, check the map and see if you need to repair auras at hint 2, else, move to hint 4 and repair auras, then move to hint 5 and kill the snowman there. After you kill the final snowman, run back to hint 2. Kill the monk first, then, if any of they huntress or apprentice got stuck kill that first. It can be lengthy to kill them, but they can't really kill you, keep an eye out on the map because if you take too long, traps and auras might need some healing.

Notes: Using the jester's wheel o fortuna when located either at South West or hint 5, is a great way to get back to tavern with style, so, don't do that. 

Make sure South West auras reach behind the crystal because during boss, an archer or orc might walk there, so, you need the auras to reach.

The 4 archers at hint 4 can fit nicely along the top of the stairs, no need to move them into there.

Why not add some sweet LTs with the remain DU you ask? Same reason you don't want to use wheel o fortuna at random as mentioned earlier.

BE CAREFUL WHEN YOU DPS AT HINT 2. If you are besides/below the stairs, a dislocated snowman can drop on your head and one shot you. Yes, that's a thing, I learned the hard way...

I put my stats for display, you can do it with lower as long as you are into the 2-3k range, more stats are nice since they can make the run easier.

Each side should take 1 wave to upgrade if you are like, really, slow. 

Final note: I farmed my first 2 diamonds using this build. I failed like 2 times, 1 because a snowman fell on me and 1 because I rolled at hint 5 and a horde of ogres partied at the crystal. If you fail, you probs did something wrong. If you somehow failed, and want to know why, or actually need help, add me on steam, my username is located above.

Happy coal mining :D