Option to quickly select quantity for selling?

Wondering if there is a way to program in the ability for a player to sell more quantity at a time instead of having to manually type in up to the maximum amount of what they have in their inventory to sell at a time. Right now we allow players to sell Scrap for RP and vise versa. This is the complaint i'm getting from our players.

Maybe a button that says max and shows the quantity that they are about to sell or somthing if thats possible, or just a quick 1, 10, 100, 1000 button or something so they could click the 1000 button multiple times and sell very quickly instead of typing in 1000 each time... 

Player Complaints:

What bothers me is that when you sell something, you have to type the amount. If I could just click repeatedly id be fine.

And then also when buying I noticed that it resets the scroll, so if I buy something at the bottom it scrolls back up and I have to find it again to buy again. 1st world problems. But annoying as he!!.

Yeah, I get a lot of the same complaints. In previous versions if you had, let's say, 4 stacks of 100 gears and one stack of 57 gears, you could just type 357 or 9999 and it would Max sell as much as you had on you.

Now, people have to type in 100 and sell each stack individually. Also, it's a bit buggy. If you just type in an amount and click sell, it doesn't seem to update what you typed in and just sells one. I was getting asked so much, I've had to make a tutorial on my Disc about clicking out on the text field first so it properly updates, then clicking sell.