Does anyone know how much it cost to hire a writer to write an "SEO" press release?

Don't waste your money. Do it yourself in the form of articles as per below details:

Search The World - Website Index

Itâ€™s rarely an instant return on the Internet. You need your website coming up relevant to what people "search for" on the Internet. It takes time to get placement in the right places within the Internet and if you're listed in the right category of searches you stand a better chance of returns. The following is one of the better ways.

For a small charge you can have a â€œPermanentâ€ website advertisement placed in an index such as this in a choice of around 750 categories to target your business trade.

This will raise your website profile and increase its chances of extra sales because this site is indexed by the search engines placing your site within "public searches".

The advantage of a site like this is that you donâ€™t have to update your listing again.
For a permanent ongoing promotion:
www.search-the-world.com/form/listing

This will only cost you $6.00 for a permanent listing that will eventually get picked up in search engine searches. You can also get a much higher profile permanent advertisement as well for $20.00. You never have to list or pay with them again.
I found free advertising sites donâ€™t work very well but this one off payment site does.

Search The World Articles

By using their new articles site:
www.search-the-world.com/articles
You can add articles about products, services or things you know about and add your website url details at the bottom of each. And these get picked up by RSS feeds and get distributed through other sites and through the Internet. You can add as many articles as you like for free. Itâ€™s all Free advertising and marketing for you!

Search The World Free Stores & Auctions

This is a Free store and auction site from them:
www.search-the-world.com/auctions
You get your own shopping store where you can sell either by auction or just like a regular store at â€œBuy Nowâ€ prices. You get your own store Url which you then need to promote yourself to get more customers etc. Promote your store Url just like you would any other form of business and build up your customer base from there. You can use Paypal. Works just like Ebay but you pay no selling fees and its all 100% free to use.