I have only bought from InlineFour so I don't know about the others.

http://www.cartunerz.com/productsdetail.asp?prod_manf=%27APEXI%20ENGINE%20M ANAGEMENT%27&cat=true ($351.20)

http://www.titanmotorsports.com/titanmotorsports/apexivafc.html ($335.00 with free s&h)

http://www.inlinefour.com/saleapexivafc.html ($325.00)

http://www.import-store.com/apexi_vafc.htm ($300.00)

Good luck.