Hello,
My name is Deniz, I am a senior web developer. I can build a script which makes connection between Mailchimp and your MySQL database in a few hours. I know that my offer is higher than your budget but building a bi-side script is not that easy.
I have 10+ years of experience with PHP, CSS/HTML, JavaScript and MySQL. I am also very experienced with Mailchimp API and I've build a similar script before.
Please send me a message to discuss the details.
Thank you.