Facebook Pages are more helpful in marketing or other type of business. Sharing is an activity carried out on a social networking site. Facebook has separated a profile and a Page to maintain a privacy for a personal profile and a public page. Any page owner will aim at increasing Fans on his page. But people who create page for first time and who have no experience in handling or maintaining a Facebook page may try to increase likes for the page than posting awesome contents. Yes, I agree. A fewer people are required to make your page to reach but but you may use invite feature or share with friends. Buying likes is against Facebook TOS. For beginners, always remember that using sites which functions 'like for like' won't give you real likes. Like you, other people also use fakes to do 'like for like'.
Facebook, without any announcement has changed the fan limit for changing the Page's name. Earlier it was just 100 but now, it is 200. This made most of the page owners to feel good. Particularly, page owners with fewer than 200 likes. Humans make mistake. Most of the users might have created a page with typographical error or you should be in need to change your Facebook page.
When you change your Facebook Fan Page name, all your Fans get notification about the change of your Facebook fan page name. This limit is more essential for Facebook and users it it. Just image, if you have any Facebook page with more than 100K friends and if you want to sell them, you may just rename it to the one which buyer wishes. Thus, Facebook levies certain limit for such activities. 
The username of your Facebook account cannot be changed once you've created. The other option which you may use for increasing likes is, merging another page of yours with same name. This may work out if you have any page unused with some likes.
Changing the name of the page is as usual, click on Edit Page in Admin Panel and choose Update Info.
Comment about this change. Is this change a reasonable one or should Facebook increase the limit?