I can do PCB layout/design in eagle.
I have mostly worked with ethernet enabled devices, based on Atmega MCU.
If I am to do the initial design and not just layout, I will probably need 15-20hours, plus expenses, for a design and prototype, well probably 2-3prototypes to get the details right, so its not exactly cheap.
I have many passives, that can be used to lower the initial cost, like 0805resistors, caps, 16/25mhz xtals, etc.
And I can make short runs in DIY reflow oven, provided the board is mainly SMD based.
However all your prices are very low, to get near those prices, you probably need bulk, ie. 4k+
To get professional assembly below 2$, even more.
6 SMD parts with RoHS assembly at advanced assembly will be 11$ each, not including shipping, stencil, etc.