There is great deal of interest in the work of the artists you speak of so for them auctions are a good idea. The have a built in market of collectors around the world and also those type of collectors are used to buying expensive things at auctions. You're talking about multi million dollar items here.

If you are unknown it seems that first of all why would an auction house be interested, but if they were, sales of your work would be by chance. A gallery which could give you good exposure to the retail marketplace would be a much better bet.