auto select prices in currency exchange

I know this was done with the best of intentions but it is broken.

Here is my example from 5 minutes ago. Chaos orbs going for 19 exalts. I have 12 of them to sell. But the lowest exchange rate is 18.83:1 so it is defaulting to the nearest even ratio so like 1000 exalts to 55 chaos. Well, I don't have 55 chaos and I cannot override those ratios. So you have to wait till an integer exchange is available and then trade 1 by 1.

Haven't tried to buy anything yet but I bet this will be an issue there also.

Need a checkbox to override the auto fill.