Hi there,
I'm a native English speaker from Australia and am glad to see that you're looking for a local to write your content! :)
I can write your 500 word blog post for you, and it will be high quality as you request (and 100% unique, of course). The grammar, sentence structure etc will be as you'd expect from a native English speaker - I pride myself on quality writing. I'm also happy to revise if needed, until you're absolutely happy with the end result.
I'd love to work with you on this, with a view to a potentially longer term relationship.
Really hope to hear from you!
Kind regards,
Rebecca