Dan, how much you spend on a canner should probably be proportional to how much you are going to use it. If you are going to use it once a year or less, I would get one of the cheaper ones. they will do the job. Now, if you are planning to do lots of canning, want to pass it down to your children's children's children, then don't fuck around with a cheap one. Get an All American if you can afford it. no seal to worry about, accurate gauges, heavy freakin' duty. will last 10 lifetimes if cared for. I have two, and would never have another kind after using these for several years.
also, you can find some really great vintage pressure canners on Ebay really cheap. my first pressure canner, which I still have and use, is a Ward's 19 circa 1950's. I got it for 10 bucks, replaced the pressure gauge and some knobs and it is fully functional and safe. total of $75 in that one.