It's a great time to be developing your own circuit boards and electronics projects! There are so many excellent free tools out there, such as Upverter and CircuitMaker that let you design circuit boards and send them out to be manufactured. While this EDA (Electronic Design Automation) software is improving rapidly, the average hobbyist is still faced with a barrier when designing boards with small SMD (surface mount) components.
Small SMD parts are no problem however if you use a professional PCB Assembly service, commonly known as PCBA.
The one I recommend is a place called Smart-Prototyping. The minimum price is $99.99 USD for a PCBA order, and that's enough to assemble 2-3 boards with almost any type of SMD part used. They will also manufacture the actual PCBs and also order components for you.
This is the quote I received for my PozESC v1.1 board:
PCBA (manual with stencil): 141.49USD
Shipping cost (DHL): 50USD
That's $300 to manufacture and assemble a 21x13cm 4 layer board with 28 THT pins, 513 SMD pads, and 44 No-Lead pads.
The best part is that you can provide a BOM with exact part numbers, and they will order it directly to their factory. The parts cost will vary with your design, but you get the same price offered on the Mouser/Digikey website. On larger orders, they will even be able to use generic versions of any passive components, saving you money!
The Smart-Prototyping guys are even nice enough to power up your boards before shipping them to you.