Dragonfire Blade Dragonfire Blade benefits from lots of ways to cheat the equip costs, but the baked in one counts the colors on say a 3-color legendary or free on Avatar Aang is all too common a scenario
Primite Dragon Ether Beryl Ultra Rare price: $29.00 Quarter Century Secret Rare price: $186.56 Primite Dragon Ether Beryl gets its hefty price by being a support card for the historically expensive Blue-Eyes archetype while also being meta in a format where Blue-Eyes is currently the strongest it has been in decades
What were some of your tech choices and "trinities?" I think they're all fairly self-explanatory, except for three things: 1: Not using a Trinity for an Unlimited card
For example, if you control this creature and Anointed Procession ("If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead."), each time you create tokens, you can choose to apply Anointed Procession's effect to double those tokens first, then apply this creature's effect to create an additional Thopter token
Bonereader is a lot better both for price and type reasons