MSN uses Yahoo owned inktomi. The results at yahoo and msn are slightly different, to learn more visit http://www.inktomi.com
You dont have to pay to be listed, paying will throw your money away. Simply exchange links with some sites that are listed in yahoo or msn and the inktomi engine should be able to spider your website. I also find that inktomi is a lot like google but without the head games. There is no sandbox, and unlike google you dont have to spam blogs to get listed high. All that you need is content on your site that reflects the terms that you want to rank well for and a decent amount of backlinks
Antoine