A little out of your budget but Digipower makes a really good one with a built in battery for $60 (112 individual LEDs) its called “The Streamer”. Its great for night with a lot of light production. If you want something under your $50 budget get something like a Godox Litemons 6r ($30), however, due to its smaller size it doesn’t produce as much light, better for filming at dusk but not night.