There's little boutiques in my area (Nothern California; whether it's San Francisco or nerdy Silicon Valley). Maybe there's little boutiques in your area. How I found these stores... I either drove around being bored, walked around and window shopped or through Yelp.com
I suggest going on (Yelp)
San Francisco Restaurants, Dentists, Bars, Beauty Salons, Doctors and searching under your city and key words like "retro, rockabilly, vintage, swing clothing, etc.". Or start a theard asking your local Yelp users where you can find it. It's free to sign up.
Also going to tattoo expo's.
There's always venders selling vintage, punk, rockabilly stuff. When I went to The Body Art Expo in the San Francisco area, they had a local vendor there.
eCharlottesWeb.com
I was walking around their booth looking at prices, and it looked decent (considering a lot of the items I have never seen).
Etsy :: Your place to buy and sell all things handmade has a lot of rockabilly inspired art work, jewlery, purses, clothing, etc. The great thing about that website is... it's all handmade goods (that means unique items). Here's some stuff I'm viewing now...
Etsy :: artallnight :: lucky in love heart dice and glitter necklace
Etsy :: wickedminky :: sugar skull and rose tattoo necklace day of the dead (dia de los muertos calavera)
Etsy :: SixKings :: Bettie Page pendant necklace
Etsy :: Bellatise :: Makeup Brush Roll - travel size
Last link is a cherry print brush roll (I love the skull & black n' white checkered ones too).
Also, never underestimate consignment stores. I don't mean the Goodwill or the Salvation Army. I mean places like...
Crossroads Trading Co. - Buy Sell Trade Clothing - Recycled Fashion
http://www.moonzooom.com/
The last link is a store that only caters to eras like 1950's-1980's. You might have a local store thats similar. At Crossroads (I have one down the street from me), they always have jewlery that is inspired by the pin-up & rockabilly.
Last but not least... headshops, tattoo & piercing shops (the ones that sell clothing are usually combined with a headshop), even Hot Topic or Spencers. Or Ebay.
Good luck on your voyage. I know how it feels to struggle finding stuff like that at a cheaper price (been there, done that).