iPad (Hobbyist) $
If you're interested in digital drawing as a hobby, you don't need to get the biggest, most expensive iPad. This 10.2" iPad is a great starting point and it's built to work well with robust drawing apps.
When investing in an iPad, my advice is to get the most storage your budget will allow.
To save a little on cost, refurbished iPads (purchased directly from Apple) are also a great option. I have purchased a refurbished iPad in the past and it still works well to this day.