I had a 6430 for a while, almost identical to yours, maybe the same. It was a nice machine, I sold it to someone who at the time needed a sewing machine asap (I don't usually sell anything, just pass things on). I regretted it after but I'm happy with my Elna now. It came with several cam sets, (sort of individual cam assembeled into knob shaped units) and did all sorts of nice stretchy stitches. I don't think any of them were cracked, and the mashine had been used a lot. In nice condition, complete with case Husqvarnas easily goes for $100 here (as in sold the next day).
If you take on 60s and 70 models you have to expect tending to a few plastic parts. By the 1950s most brands used a few plastic gears, by the 60s all metal machines are few and far between. These machines can be very nice and worth it, but only to someone who fix them up to use them. It's not easy to sell them on for much more than it took to fix them up.