I bit the bullet and payed for the upgrade. Of course, with the business I really had to and it's easier to justify for me. It works well for Trad Gang, and the pictures can stay out there on your old threads. If you delete your pictures and someone pulls up that thread from a search all they will see are the little red "x" in a box.
It's great that photobucket is free for most users, but eventually every business needs to get paid for something, and Photobucket is a business.
I know there are other free sites out there but don't know anything about them or which ones to recommend. Sometimes I have seen people post pictures through some other sites that require the viewer to click each image or visit another site to view them, and those aren't as user freindly as Photobucket for the person veiwing them.