Free, seo. Test out some long tail keywords with PPC and see if they convert then go for them. Even if you are new [to seo] you should be able to rank top 5 with a low competition converting keyword. The term might only get 5,000 searches a month but if you get a good conversion rate you can make bank. It really isn't that hard. Go for it and good luck.
Good idea. I will create landing pages till I get dinged by the Big G.