Article/Blog Copy Writing

I am looking for someone to write a article/blog of around 300 words on a product that allows natural light into your roof, these are call roof lanterns, skylights.
I am after someone to write for me on a regular basis, so if your first attempt is of good quality I will need another 3 writing by the end of October.

If you can provide me with a price for the whole article rather than per hour that would be great.