Ignoring the time and cost of labor, the system cost is ridiculously low. The most expensive item in the system is the TI module, which costs around $60. All the other components, the materials for the PCBs, and the items needed for building the loop antenna, together cost at most $40-$50, giving a total cost of $100-$110.

Cool Paper. The cost of time and labor, however, should not be underestimated.

How to Build a Low-Cost, Extended-Range RFID Skimmer