An example of where someone asks you to pay money to get money is reflected in a recent FTC Alert where a scammer poses as a government official to get you to send them money. I encourage you to read more below to see how this scam works.
The scammers in this instance are pretending to be calling from the National Institutes of Health (NIH). According to reports, callers are telling people they’ve been selected to receive a $14,000 grant from NIH. To get it, though, callers tell people to pay a fee through an iTunes or Green Dot card, or by giving their bank account number.
If you get a call like this from someone asking you to pay money to get money; STOP, and hang up the phone. The federal government will not call you to give you a grant. NIH does give grants to researchers, but they have to apply for them, and those grants are for public purposes, not for personal use.
Again, as I have recommended in the past when receiving a telephone call do not answer the phone unless you can positively identify the number. If you do not recognize the number, let it ring through to voicemail. Once a scammer has a live person on the phone, even if you do hang up, there is a high probability that you will be called again, for the same scam or for a different one.