C00kie M0nster
Member
I've already added a few sorting / filtering options to the wishlist that somewhat alleviate this. I'm planning on adding checkboxes similar to the ones I put on store pages for lists of DLC. As with those check boxes, there will be an options panel that will allow you to select games in bulk by certain conditions (such as "Under $5", etc). Then there will be multiple buttons at the bottom such as "Add Selected To Cart" or "Remove Selected From Wishlist".
You mention that you have a large wishlist and that the "Buy Wishlist" button is gone and that's probably the cause. Steam sometimes times out on this request when you have a lot of games on your wishlist, usually people start seeing problems when they have over 200 games on there.
Awesome. That is great to hear and can't wait to see what you come up with next.