My new cheap-o brushed satin black 8mm tungsten band that arrived last Friday from an eBay seller for $8 shipped after sales tax...yes, you read that correctly! We'll see how long the finish holds up.
I recently purchased a 14kt 4mm rose gold comfort fit band from Sarraf for $279.
To be fair it's listed with an approximate weight of 5.50 grams and an approximate depth of 2mm. Mine at a size 6.5 has a weight of 4 grams and a depth of 1.5mm.
While I'm not thrilled with the discrepancy, I can live with it for the price as I have several bands that I switch around.