You may be able to "hire" a writer in exchange for some benefits.... maybe you can give the writer a dedicated "about the author" page along with a short bio or at least byline at the bottom of each article created.

As far as Adsense revenue share - that's a possibility, but you would probably want to make it so that the author only receives credit for their own posts. However - your blog seems like it's kind of new (or at least not very visible)... I don't know what the likelihood is of grabbing new writers based on revenue share when you don't have much, if any, website traffic.

By the way - it is possible to have revenue share for a single post, you just have to talk to your programmer about that.

As far as how much a blog post is worth... that's really dependent on how much value it'll bring to you. Based on a cursory look over your blog it seems your posts are quite short, have a lot of links and the occasional image. While the writing may not take a lot of time in and of itself - the research to find the links and images may take up some time... you're probably looking at 20 minutes to 45 minutes per post, depending on the writer.

Most writers I know charge by the project, not by the hour. If I were to bid on this myself with the information I have now (which isn't much) - I would probably say around $17.50/post if it was a long-term gig and more if it was a handful of posts (maybe $20/post). However, I don't really know what the market rate is for writing services - I'm a writer but I don't necessarily charge the market rate, I charge what I feel comfortable with and find people willing to pay that price.

I think your best bet, though, is to find writers who need to establish themselves. Give them a byline or a short bio and you may be able to get a regular writer for a season until your cash-flow situation changes.