Seriously?
Just look at what you're asking. "I'd like a blog post on Mashable today, please". It's like saying "I'd like to be featured in the Wall Street Journal" or "Where the smeg is my Nobel Prize for SEO?"
You don't just ask how and how much. If you want to get featured on Mashable, you have two options.
1) Blackmail the editor - Either through love, money or compromising photographs. Even if you have a substantial amount of money, what's the guarantee that it would get on the site/stay on the site? If they see this crap article promoting a crap product/website written in crap English, the editor's gonna get interrogated over it. Why would they put themselves at risk?
2) Create something fucking awesome. Something that people wanna talk about, write about, share with their friends. Socila sharing is a massive part of mashable (look at the overkill on the sharebanner), so your content really needs to have the potential to go viral.
From your original post, I'd say you're a long way from this mindset.