www.wysiwygwebbuilder.com

I have a client who has an art collection he wants to auction off, I suggested eBay or a company that does that but he doesn't want to pay the commissions since some of his art is valued over $20,000. After a little research I found a plug-in for WP, but I hate WP with the heat of a thousand suns. I bought it for $40 anyhow, just to get through this job, but I am having too much trouble getting it to work right, and the limitations on image sizes in the galleries are prohibitive for a fine art site. I'm considering making one with our trusty WYSIWYG builder, with user registration and a form driven bid process. It would be nice if I could set up an automated notification when a bidder had been outbid, but I could also just manage that through emails manually. Are there any tools or plugins that might be suited to the task? Thanks in advance for any suggestions you may offer!

I would be tempted to smack the client over the head with his keyboard and push ebay - with all of its protections built in - and just pay the fees. Especially with the values the client is claiming his art will draw.
Beyond that, I can't help you. Good luck.

I'm sorry, there is no standard solution for this. This will require a custom script.

This one is good:
https://www.phpjabbers.com/php-auction-script/