I got one from Amazon with the mag stirrer and variable heat control. I think it was $40. Some just have high/low heat settings. You don't want those. You can get away with not having the mag stirrer, but then you should have glass stir rods and you have to hold the hot beaker (or use a ring stand). I just use the mag stirrer so I can do other things (get filters ready, etc.) while the powder dissolves.