Thanks for the info. I figured out that using a CSR chip was going to cost $10K+ a developer seat. The chips are cheap but the savings is eaten up with the dev tools.
We have switched to an 802.15.4 chip, the Freescale mc13224v. You can program it for free using gcc and contiki. It is the best bang for the buck until the Ember 351 ships. Ember 351 may need costly dev tools which may ruin it’s cost advantage.
We are using 6lowpan and TCP/IP instead of ZigBee. We want to be standards based and ZigBee is not open. 6lowpan is available for free in Contiki. I had ipv6 running in a few hours.
We also evaluated 802.15.4 offerings from Microchip, Atmel and TI before choosing Freescale.
These guys offer pretty cheap mc13224 dev boards.