Layla the Ball Python & a few questions :)

[Sekani]

An Acurite thermometer/hygrometer at Walmart is $15. Do you have the heat tape on any kind of dimmer or thermostat.

Unfortunately we don't have cheap shops like that over here in Ireland (unless anyone wants to point me in the right direction?), was looking around at prices and they're around €16 for a thermometer and hygrometer each I know that may sound like not much to you, but over here, that's a weeks food for myself and my boyfriend!
Was looking on ebay, and I'm kind of hesitant as I'm not sure what constitutes a "good" one or not... What do you think of this one? Does it look any good? I hope don't sound like a cheapskate!!
http://www.ebay.ie/itm/Digital-LCD-T...#ht_1016wt_909

The heat mat is just by itself, plugged into the wall.