That question doesn't make any sense.
The dossier was a collection of intelligence gathering by a reputable former MI5 operative with a decades long legit track record of cooperation with FBI/CIA. His work was initially funded by a conservative newspaper, then other parts by the Democratic campaign. The contents of the dossier were passed to the FBI, who deemed it credible info. Who paid for the initial probe into Trump's foreign contacts and dealings is irrelevant. The content and credibility of the information that was unearthed passed the smell test at multiple levels of the FBI, who proceeded to open an official investigation into the allegations. Which is their duty and obligation to do so in a case like this. It seems you are confused about some basic aspects of this case, and the genesis of the dossier. Which would explain your flippant attitude about it.