Is your feature request related to a problem? Please describe.
Not really a problem, more of a minor time save when posting auctions. The "problem" is having to manually swap the values in the "stack of" fields.

Describe the solution you'd like
The solution would be to implement a button to perform this function automatically. It's a small time save, but this is by far the most common manual input required for me when batch posting auctions, so being able to automate that functionality would translate into quite a nice time saver in the big picture.

Describe alternatives you've considered
An alternative could be buttons to set either field to a value of 1, because scenarios where the swap button would be handy almost always have a 1 in one of the fields. Perhaps two buttons under each field, a "1" and a "max" to manipulate each field separately.

Additional context
Attaching quick markups of proposed solutions #1 and #2.