I've entered a league.
$100 to play for a year... starting with a $20 budget. (mtgprice.com with some rounding applied)
Each week, additional value towards deck construction can be 'won'... all players will win some value even if you don't win any games.
This is the starting deck I've entered. (Will link to 'current' deck after my first 'new cards' are added)
Aluren + Cavern Harpy + Parasitic Strix
= Instant win. - Can go off as early as T3 with a T2 Explore or Coiling Oracle for an extra land.
I find the combo is quite resilient to removal, as it can 'bounce' to save itself.
Lim-Dul's Vault is an all-star, getting combo pieces from anywhere in my deck, at instant speed... Opt is also quite strong.
With a $20 limit, Aluren is only a 1-of... but will be the first cards I save up for more of.
Killing/Countering Aluren would kill me, so the Reclaims are required at first... they will be removed for the Alurens, as they are easily the worst cards in the deck.
Mana fixing is also difficult with 3 colors, so I will be getting Evolving Wilds soon. (Most other players are only 1-2 colors)
I have little removal, but am considering Displacement Wave
Currently about 75% win rate.