The most typical scam is: "If you send me money for airline ticket and visa I can come and see you."
It is almost impossible for these women to get a visa to the US or most other countries. The only real way is for you to apply for a fiancee visa. If you still going to buy a ticket use a credit card and have her pick it up. If she say that will not work you are being scammed. A sincere women will not come to your country until she meets you in person. Many scammers will also say they have a friend at a travel agency who has connections. Do not believe it.