This makes me upset! I hate to see you or anyone else pay extortion fees to Photobucket. I understand nothing is free and bandwith/storage has its cost, but $400 sounds more like mafia protection than a legit service fee.
Unfortunately, solving this problem requires a two-fold solution: moving forward, and moving backward. Moving forward, it's easy to switch to a more reasonable image host. Hosting
yourself would be most ideal, because then you'd never potentially get involved in another protection scheme again. I mentioned it in the other thread, but I've been using
DigitalOcean for all my hosting. Their pricing is very reasonable, $20/mo gets you 3TB of transfer and 40GB of storage. Running something lightweight such as nginx would make it so you could serve images quickly with no overhead. Plus, it's under your control with no ads or unpredictable fees. Granted, I don't know your requirements here. How many GBs of images do we have here? How much traffic are you seeing? These are not things you have to disclose in public, a PM would do if you felt like sharing.
Okay, but also moving backward. Moving away from Photobucket means lots of potential broken image links here, something you're dealing with already. Again, if it were me, I could solve the problem myself. Dump the forum database somewhere and then write a script that finds Photobucket links and replaces them with links to your new host. Reimport the database and that should take care of it, no more Photobucket.
Please let me know if I can help you with a solution that means giving no more money to Photobucket! I'm not even trying to make money here myself, I would just like to lend some experience if I can. I've certainly benefitted from yours over the years.