Get this Honeywell 7-Day Universal Touchscreen Programmable Thermostat for just $39 (Retail $129).
This thermostat is easy-to-read, easy-to-use and works with virtually all systems! It features vacation hold which adjusts to the normal settings upon your return and more!
You must opt for free in-store pickup if available near you or shipping is $35 or more. At this time I did find some available for pick up in the St. Louis area.