I only find out yesterday that tickets are on sale for Black Sabbath's North American tour, and when i checked the concert for Calgary they seem to be all sold out. The floor ones are anyways which is where you wanna be really.

But i got forwarded to sites like directseats.com and theicketexperience.com that seem to have a load of tickets available and for decent-ish prices for ground floor tickets.

I am always a bit weary about buying tickets that arent from places like ticketmaster or official sites. Has anyone ever used these sites? And how do they work, is it like a seller site where uses sell their tickets or have the websites bought up all the tickets?