InkBird is about $35 and gets tons of praise over on SimplyDiscus. I have one for my large tank and the programmability is great and it's very easy to use. It also has low and high temp alarms.
At that price I guess there really isn't much of a reason not to use them if only to save yourself the headache of the cleanup. I've not used the inkbirds but the ranco units are solid, they might take more wattage and be more ideal for larger tanks then.