I'm looking for a very low cost barometric pressure sensor. The SCP1000-D01 available at Sparkfun and elsewhere is around $25 but I was hoping to find something in the $5-10 range. I am only interested in rough relative pressure change, so it does not have to have high precision or be calibrated. Basically something like the thermistor equivalent for pressure...
Futurlec has a few barometric sensor in the $5-10 range. These use I2C interface though, so a bit more involved in the MCU side than a simple analog voltage.
If you're in Australia, you can buy from their Australian website as well.
I would take a look at the sensors from Freescale. I bought an MPX4115A from Mouser.com for about $10. This is (supposedly) suitable for use as an altimeter; I haven't gotten to that project, yet. :-)
You can check out the Bosch Sensortec BMP085 sensor. It is SMT, but it gave me good results.