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As long as you can toggle between high and low heat, I think you're set. I purchased this one for $20, but this one is about $13 and does the same thing. It holds 3 quarts instead of four, so if you're making large batches of HP then you may need to find another.
A lot of soapers also head to their nearest thrift store. If that's an option for you then go for it!
You can also do HP over the stove with a super cheap stainless steel pot (I got mine from Walmart for $6) if you're comfortable with that.
Proctor-Silex 33043 4-Quart Slow Cooker [link]
This is the slow cooker I've used for the years. I warn you that you might want to throw open a window before you cook because after four hours whatever you're cooking is going to permeate the house.
Woods 50006 Indoor 24-Hour Mechanical Outlet Timer, 2-Pack [link]