I have paid for the services of a medium, and I am also a Tarot reader, for which I get paid. And yet I will be the first to say that a very high percentage of those claiming to be mediums or readers of any type are scammers.
I would advise anyone seeking answers to try to get a personal recommendation from a friend, the same way you would for a plumber or auto mechanic. Lacking that, go with the combination of an open mind and a closed wallet: Do not be talked into paying to have your aura cleansed, your mojo mended or your angry dead great aunt assuaged. The medium or reader should ask to be paid only the agreed upon price for the session. Further sessions if you desire such should cost what the first did (although I have also offered a discount for followup sessions).
If you get the hard sell to add on a pricey "emergency" extra, leave. A reputable reader will not play that con--it's one of the oldest in the book and while it has a venerable history, it remains the height of sleaze.