THE AMD socket M2/AM2 based motherboards aren't likely to cost very much more than existing sockets. AMD advised its motherboard partners that the new motherboards will cost them only a little bit more. Socket vendors can make those sockets with small tooling changes to existing Socket 939 and should keep the cost to N almost equivalent level.
Socket AM2/M2 boards will use DDR 2 DIMM sockets only, so you can say goodbye to DDR 1 memory. DDR2 sockets have been around for more than two years now, thanks mainly to Intel of course and their cost is already equal to DDR1 sockets. No change here.