I first started playing Dota 2 in 2014, where battle pass(compendium) cost around 8$. You can reach 100-200 levels without purchasing any levels. Also, you could get a few treasures, and by selling those you would have 50-60$. You could use that money to buy the next battle pass and some games on steam. But in the past couple of years battle pass they its become impossible. Immortals are marketable after the next Ti Final. Some of the item they made exclusives. Even last year side shop, every item was instantly marketable.
Battle pass items except cache set all should be marketable.
Ditech Gaming currently has 1,795,007 views spread across 397 videos for Dota 2. His channel uploaded over 1 day worth of Dota 2 videos, or 19.78% of the total watchable video on Ditech Gaming's YouTube channel.