isyndica.com  have just announced a restructuring of their pricing. I reviewed isyndica a couple of months back and since then I've been using it as part of my normal upload workflow. One of the only gripes I had at the time was the price, but now things have changed.
Update: iSyndica have announced a contest offering the chance to win $200 Apple gift cards 
Pricing starting at free!
There is still a free isyndica account which offers 100 free credits per month (an image upload to a chosen agency is one credit, ten credits for a video). You can now buy prepaid credits that never expire for 1 cent each, the minimum purchase being 500 credits for $5.
Prices for paid subscriptions have reduced, now starting at 4.99 per month which gets you 200 credits, again you can buy additional upload credits for 1c each.
Backup storage included
Paid accounts now include the bonus of secure backup storage of your images along with stats/analytics of your sales and custom FTP  upload channels (syndicate to any agency that supports ftp).
If you only want to upload your images to any of the 21 supported image agencies (as of 30 July 09) or 7 supported video agencies then a free account is all you need, paying for additional (more than 100) uploads as you need them.
I always like to highlight both benefits and any negatives of services I review, with iSyndica I have a problem, the iSyndica team keep adding new features to the site. The lack of support for secure ftp / veer marketplace was a minor issue as was my complaint about credits expiring, both have now been fixed. So far I have found the service reliable and a big time saver, I really can't think of anything bad to write.