Just a few days ago, I had spent WAY too long on the monkey business page. Why? Because I had just too much to sell from my buried hoard! and having it refresh whenever I sell an item, when you have a poor internet connection or a slow compute is hellllll.
And yes, I was using bulk trades, I wasn't going through every single one. It got to the point that I just threw most of it out.

This is a massive inconvenience to everybody who gets most of their money from selling. And i've seen a ton of topics addressing this that get no attention after a few days.

I know some issues will come up, So ill answer ones that come off the top of my head.

Q: it ill take too long to code!
A: no. Thats not a valid reason why they shouldn't do it. We have the same option in the hoard organizer to thrown everything checked out, or put into the branch.

Q: What if I miss-click?
A: Why, there would be a warning that pops up, making sure you want to sell everything and how much it will give you to do just that!

Q: Lioden just wants you to spent more time on their site!
A: dude. no. stop. Lioden does get money from advertising, but 1/3 of the time, its not Pay Per Impression. im unsure what Payment Schemes lioden uses so i cant answer this with confidence.

Q: I wouldn't use it, so that means no one else will! I dont like options for other people!
A: : / dude. nooooo.
you wouldn't have to use it, its not a thing that replaces bulk sales. It would just be a convenience for people with 30 different items they need to sell off

Please! dont disagree without leaving a comment, so I can answer any issues.

---------------------------
Lusitano also suggested that there should be a mass-donate button for clans

Heda RedBox:
Another thought would be for either a tick option like you said, or a select various (with Ctrl+click) like when you transfer items to other players.

*This [Ctrl+Click selection] could be implemented to both single and bulk sale