You can get a barebones arduino for around 3-5 dollars. Shield (without any price comparison shopping whatsoever) is 49 bucks (http://tronixlabs.com/arduino/sh

You can get a barebones arduino for around 3-5 dollars. Shield (without any price comparison shopping whatsoever) is 49 bucks (http://tronixlabs.com/arduino/shields/gsm/sim900-gsm-cellular-shield-for-arduino/ http://tronixlabs.com/arduino/shields/gsm/sim900-gsm-cellula...). Siemens has an arduino compatible GSM module for 29.99 (http://www.sainsmart.com/siemens-tc35-sms-gsm-module-voice-adapter.html?kpid=13_en http://www.sainsmart.com/siemens-tc35-sms-gsm-module-voice-a...). So 33 bucks and a free "That was easy" button from staples and there you go... that's at single unit price. BTW, for vast majority that is likely beyond their capability... so maybe 77 bucks is worth it? I dunno.