I'm always looking for ideal low cost serial adapters, this is my latest find from AE costing just 0.67 ukp each (shipping extra)
A unique feature of this device is that the handshake lines are brought out to pads which can be easily soldered to any required pins on the D connector. In this photo I have wired it for RTS/CTS with jumpers on the header pins to verify operation.
Edit, Oh yes, and it has the correct polarity to plug into the back of a PC, i.e. 9 way D socket.
hth David.