Don't play Ranked if you aren't going to pay. People try to use examples like, "Trump got to Legend without paying a dime so that proves that this game isn't pay-to-win!"
I find that to be just a senseless and stupid representation. "Because someone did something, that proves it's possible." Yeah, clearly, but enjoy your 0.01% chance of it happening.
People polarize too much, as if "pay-to-win" means that if you pay then you will be the best, and if you don't then you won't be the best. No, if you pay you will have a huge advantage over others, and if you don't then you won't. Only an idiot would try to argue that it's fair when you queue up for ranked and you're against a Mage running 2 Malygos and 2 Antonidas (because they spent $200 on packs).
Just do what I do and either play Casual, or don't take Ranked seriously and play it for the 500-games achievement per hero. Use those play modes to farm for gold through your quests, then do Arena runs. Arena is way more fun.