Other than cost what’s the difference between a Hofner H500/1 Vintage 1964 & a Hofner Ignition Pro?

Well...
- The Vintage 1964 was made in Germany. It will have German hardware, strings, and pickups.
- The Ignition is made in China. It has Chinese hardware, strings, and pickups. However, it's made under Hofner supervision, so it's well made - usually...
- The Ignition is made to a price point; a fairly low one.
- The German Vintage 1964, for all practical purposes, is not. It's made - by hand - like a violin or a cello. Which is labor intensive, and therefore expensive.
That said, unless you just absolutely have to have a vintage-y, old fashioned craftsman-made instrument? There's not a thing wrong with a 500/1 Ignition. I bought one of them a couple of weeks ago, in fact. I'm impressed with the build quality, and the way it plays and sounds. Is it just as good as a German Hofner? I've played a German 500/1 a time or two, and IMO... no, not quite. On the other hand; given the price difference, is the German one 6 1/2 times better? I'd have to say no; no, it isn't. But, that doesn't mean I wouldn't like to find a good deal on a German one - and, I'm a lefty, too.

 

Well if you find a really cheap righty you can convert it to a lefty, those basses are one of the few where this is actually feasible

 

The HI BB / Ignition is very good, especially for the money. If you put a good set of flat wound strings on it ,it has the Hofner sound. I've owned many German-made Hofners over 50 years. I currently own an Ignition with Labella flats for the Beatle Bass (special size) light gauge and it sounds quite good. In fact better than I expected. I also own a CT version of the 500/1, which is very well made, and plays beautifully.
Only you can decide if spending more money is worth it. Most of us play them using only the neck pick up for the classic tone, but that depends on your likes and needs. They German made Hofners are beautiful.