Ask your friends to like the page and then start posting useful, interesting information so that they share the links and bring it to the attention of their friends etc. Until you get established I wouldn't go anywhere near the commercial fan buying options.
Normally, people post related only to their business, so they do not get reasonable fans. You should also post other interesting materials, whether it is related to your business or not. Which not only increase your fans but also decrease your chance of being spammed.
What i do is i first of all invite my friends to like my page once i have friends and page shows some likes (100+ ) i start advertising , no one would like to be a a fan of a page with zero likes ....
There will be some problem in Attracting people you are targeting. so give more efforts in that direction.
there are few useful tips I can give: 1) always post most relevant stuff and as your fans are too rare so give min gap of 40-50 minutes between 2 posts, else try your level best to post more frequently, but try to avoid 3 posts within 1 hour, that will have spam image. 2) Invite your all friends and also request to your friends that they may invite their friends as well. 3) In start buy few fake fans so real fans can be attracted as its human nature, when more people are saying its good then we start liking and f there is no body already liking or lets people are liking then we can have quick image that it won't have worth to like it. 4) Don't do robotic posts, try to engage with your fans, give them value.