Ha! I have an MA in Professional Writing - and am good - and for sure I can write 300 words in 10-15 minutes.
I'm sure you could. As can I. That wasn't my point.
Be aware that this position requires you to do your own internet-based research before writing the estimated 300 words. Factor that into your time/pay equation.
I'm another who could pump out 300+ words in 10 minutes but to actually craft something that is worth reading or paying for takes me longer. No way would I be prepared to do background research or even read and digest a brief if I am only being paid for the writing time at low rates.
but I don't think I could pump out this kind of material in 15 minutes (and I'm used to churning out stuff in a pressure cooker environment). Also, I imagine some prelim research would be required. Even if background material is provided, then some time needs to be spent reading the material and digesting it.
I agree with a previous comment that it's not about reaching 300 words, but rather how to get it down to 300 words and make each word pack a punch.
It's not about coming up with 300 words. It's the research that will go into it, then paring down the relevant information, while utilising SEO and still making it sound good. It's a whole other ballgame.