Constant Content

I'm fairly new to the site and have only sold a handful of articles so far. I recently applied to a casting call, pitching two ideas. Only after I'd applied did I learn that the pay was only $15 ($10 for the writer) for a 400 word article. I wrote the article, then through two revision requests, learned that the client also expected a half dozen links as well as a photo. I spent hours researching, writing, re-writing and providing more links, so lost rather than made money on the article, which still hasn't been accepted by the client. I've decided to just write and submit articles rather than applying for any more casting calls, but I'd appreciate any suggestions from those with more experience here regarding casting calls and writing teams.