don’t buy used, buy refurbished direct from apple.
This one fits the parameters:
Or this one, which leaves enough room in the budget for an apple pencil, and maybe Applecare, and don’t forget the camera adapter so you can plug it in to maintain a charge while performing in addition to connecting peripherals/controllers:
General rule of thumb is to buy the newest you can get within your budget, so eventhough they were released at the same time, the Air has the newer/better/faster silicon, so that puts the bullseye squarely on the Air. It’s a newer processor, and will be supported by both Apple and algoriddim a bit longer, bluetooth 5, a screen that’s a smidge bigger.
@tdez I agree with @heysoundude and @LaidbackFred. Buy the most powerful device you can afford. Given that you mainly plan to use streaming services, you could choose a device with less storage, but newer processor.
For reference, I’m currently running djay Pro AI on an iPad Air 4 and iPhone 11 with zero issues.
Also when you get your “new” iPad here are some tips to maximize performance and stability: