Recommened chips for datacommunication over a low-voltage AC power line?
Since you mentioned ASK in a comment, the NXP TDA5051 is an ASK modem designed for home power networks, and operates at either 600 or 1200 baud, which is in between your 100 .. 10K baud range.   It is RoHS compliant, and is available at Digi-Key for under $3 in quantity.  The interface circuitry required seems to be fairly straightforward.