I am looking for a low-cost (< US$500) GNSS/GPS setup with a centimeter precision without much HW hacking. I am not able to produce my PCB or do any soldering (though I would do that if there is no other way) so a kind of a easy-to-assemble setup would be welcome. I know about the $900 Piksi thing but that is still too expensive for me. It seems like cm precision should be possible for much less - like employing a 50 USD raw GPS sensor with an antenna and ordinary PC with RTKLIB software.
I am not sure if it is better to use two GPS sensor setup for RTK (one base station and one for rover) or whether I can get the corrective DGPS data elsewhere (my region is Czech Republic - there seems to be national grid here allowing to stream correction data for reasonable cost).
My application will be in a passenger car so I will not be limited with power source - no low power needed although that would be nice. I will be using the position readings within OpenCV - so I need to get the data into C/C++ code. The application is data collection so I can use raw GPS post-processing.
EDIT: I was recommended a $150 U-BLOX LEA-6T USB board that would make a $300 sum for dual unit setup without the host HW (probably 2 x PC or Raspberry Pi?) and software. As software RTKLIB could probably be used although I have zero experience with either (HW & SW) of these.
Also, there seems to be the NAVIO board from EMLID in development and hopefully to be released soon. This will probably offer an "out of the box" RTK solution (both HW & SW) at an estimated price of $165 for board (see comments on that link). They made some RTK demonstration (theory here) and also some Real-time OS tests.