Binance does it like this: <img width="200" alt="image" src="https://user-images.githubusercontent.com/112318969/228267261-710c5cf2-a9b6-465d-9d4e-456505944284.png"> On dex there is one caveat with Market buy order where `qty` is denoted in the opposite currency: <img width="298" alt="image" src="https://user-images.githubusercontent.com/112318969/228267865-71297529-83f3-4e36-b591-215cbefc8e22.png">