Amcor might not be a famous GPS manufacturer, but they certainly have a decent line-up that covers the $150 to $280 segments. I would argue that there are too many models for such a narrow price range, but I noticed two that are interesting:
Amcor 4400 ($180)
AMCOR 4890 ($280)
I haven’t tried one, but they seem to use the same navigation software than the Mio GPS do, and therefore, you should get a similar experience, provided that the hardware is equivalent. Read the Mio C320 review. Check the whole line-up at Krunker. Amcor website.