I was going to just plant an aluminum plate under mine, and use the household iron on it. Thermostat equipped, and I already have it.
Some of the guys on castboolits are just using a small desk or bedside lamp, placed close to the lubesizer a while before starting. They say it works for them.
A fella could probably scrounge up a coffe cup warmer or two, and set himself up with a pretty decent rig, if he wanted to be frugal about it.
Auberins.com sells controllers and thermocouples for pretty reasonable, if a guy wanted to go high-tech.
Cheers
Trev