In the United States salons are charging anywhere from $5 to $20 per feather depending on the quality of the feathers.
The salons in the UK that buy from our company have been charging £5 to £10 per feather for both the long skinny and long wide feathers. Super premium feathers of 12 inches or longer are absolutely in the £10 to £15 range each.
Feathers must really be starting to go crazy in the UK, we've received hundreds of orders in just the last few days.
Feel free to ask any me anything about feathers. We have lots of data we can share such as most popular colors, lengths, demographics, etc. I'm an employee at HauteHairFeathers.com in the United States. The feather extension trend has been big here for over a year now so if I can't answer your question, someone at our company surely can.
A bit of useful information - The feather quality is generally defined by the width and length. Top quality feathers will be slightly wider, similar to the width of a pencil. Many feather retailers sell feathers that are called "midge" feathers - they are very very thin and not nearly as attractive.
Another pitfall that first time feather buyers fall into is buying non-genetic feathers. There are many companies that sell "rooster feathers" - they are very stiff and webby, not suitable for hair extensions.
The third and final pitfall that many salons run into is feathers from their local fly fishing store. The factory dyed feathers you would find at a fly fishing shop do not have 100% permanent dye. It can run out into your clients hair and stain it. Color correction anyone?
Avoid those three major pitfalls and no matter who you buy from you should do well - feathers are beautiful and a VERY lucrative product for salons and stylists.