I'm a NA fan and I envy the EU cause they have a lot of amateur leagues that gave players the chance to compete at a high-level. I'm a huge believer that the LCS could help to create a good amateur scenes in a way and help NA to have success in the future.

So, my idea: NA AMATEUR LEAGUE

Regions:
East - Central - West
8 teams in each region. For the first season, the best 8 team are qualify by the Open Qualifier.
After the 1st season, 2 teams by region can qualify via an Open Qualifier and have the chance to fight for a spot in the league.
*In the future, the NA Amateur League could expand and add some of the Latin America.
**You don't need to stay in the region where you play. Game hours will reflect the best time for the region. (For example, a East player could play in the West Region, but if his game is at 7 pm PST, he'll play at 10pm EST).

Season:
Bo1 (double round-robin) for an 14 games season.
The first 6 teams qualify for playoffs. 2 bottoms team need to requalify.

Playoffs -> Bo5
Same as LCS
G1: 3rd vs 6th
G2: 4th vs 5th
G3: 1st vs Winner they choose
G4: 2nd vs the other team
Third place match: Loser G3 vs Loser G4
First place match: Winner G3 vs Winner G4

How to qualify after first season-> Bo5
G1: 7th team vs Open Qualifier finalist
G2: 8th team vs Open Qualifier finalist
G3: Winner G1 vs Winner G2 -> Winner qualify
G4: Loser G1 vs Loser G1 -> Loser isn't qualify. Winner play G5
G5: Winner G4 vs Loser G3 -> Winner qualify

NA Masters

Round-Robin
Best 3 teams of each region are qualify for it (9 teams)
One week tournament.
Three pools (P1: East 1, West 2, Central 3, P2: West 1, Central 2, East 3, P3: Central 1, East 2, West 3)
Bo1 double round-robin (face each team of your pool 2 times)
The best two team qualify for the next round.

Playoffs
Six team double-elimination. All matchs are Bo3 except the final. Final is a Bo5, simple elimination.
The two teams with the most win will start Game 3 or Game 4. If more than 2 teams have the same number of win, the quickest victory is the tiebreaker.
The finals could be a live event in the LCS studio.
Example
G1: East 2 vs West 2
G2: Central 1 vs Central 2
G3: East 1 vs Winner Game 1
G4: West 1 vs Winner Game 1
G5: Loser Game 2 vs Loser Game 3
G6: Loser Game 1 vs Loser Game 4
G7: Winner Game 3 vs Winner Game 4
G8: Winner Game 5 vs Winner Game 6
Third place match: Loser Game 7 vs Winner Game 8
First place match: Winner Game 8 vs Winner Third Place Match.

Budget

Riot or LCS team could give each team a budget when they qualify in the Amateur Scene (like 15 000$ (for a team, that represent 2 000$ by player, 500$ by sub, 2 000$ for the coach, 500$ for his analyst). The prize pool is 40 000$ for the regional league and 100 000$ for the NA Masters. (Total cost of the Amateur League: 500 000$)

For 10 LCS team -> (500 000$ / 10 = 50 000$ by team as contribution)

Rewarding growing talent

For helping the team, you could add some bonus for the team that help grow talent. If one of your player signs with an Academy Team, the organization receive 10 000$. If the player reach LCS in the two next years after signing in Academy, you receive 50 000$.

Casting

The cost of that idea will be less than the Huni contract. You can recruit amateur or independant casters and paid them by game they cast. (add between 50 000$ and 100 000$ for the production/casting, so around 250$ of casting/production cost by game for an scenario of 14 regular seasons games for three different league with 8 teams)

PS: Sorry for my english. I'm French Canadian.

TLDR: Investing a small budget in a amateur scene could help NA to develop players in the future.