No you don't. If it's clear you'll win, your lawyers will take their fee out of the expected settlement, often as no-win-no-fee.
That's why individuals routinely take the big businesses to court and win - even when the upfront legal cost of doing so often vastly exceeds the amount of cash that the individual has.
Ideas without products are a dime a dozen and should not be protected.
That's why you can't patent ideas. You have to patent inventions.