This is a huge pain.
Crowdflower is expensive and lot of workers complain that they complete a whole bunch of work and not get paid, it's been marked by people on reddit.
Amazon HITs are really the only way to go. Unfortunately, its very difficult now to get on Amazon.
We are definitely more expensive than turk, although we have big discounts for small startups that makes us comparable.
For your information, I am basically doing photo tagging, wondering what my costs will be, how fast jobs will be completed etc.
Thank you.
Looks like Lukas might have missed your response but I can jump in. We definitely love to work with the little guys, too. Nothing is more interesting than the use cases that academics and startups come up with. You should reach out to Lukas via e-mail (he shared it elsewhere in this thread) or our sales team (http://www.crowdflower.com/platform-plans) to talk specifics.
We've also got a trial that will let you process 5,000 rows of data without having to worry about a paid plan. It's not time limited, either, so you can take as long as you need to go through those first 5,000 photos of yours.
You might want to check out a recent blog post up about a photo keyword gen job run by one of the guys at CF: http://www.crowdflower.com/blog/how-i-got-the-crowd-to-gener...