Make sure you’re familiar with how to maximize the rate of materials, we all have blind spots
https://forum.smallgiantgames.com/t/list-of-ways-to-acquire-unfarmable-ascension-items/61138
And it’s quite possible to play for free, with effort and good fortune. Here are some absolutely stonking freely acquired rosters
https://forum.smallgiantgames.com/t/who-has-the-best-f2p-roster-in-the-world/68800
Good luck, however you decide to proceed 