The issue isn't about the amount, Regardless of whether it's 2 USD or 20K USD, as long as the size in bytes and the total fees are reasonable with the network TX level it will get confirmed.
For the current TX time, I would say something along the range of 30 Satoshi per byte minimum, if you want it confirmed within few hours, but with 4,6, it wouldn't be strange to have to wait for days until a miner include it.