I have had a Navigon for many years. It was £113 and included maps of the whole of Europe, including - for instance - Albania. The price included map updates for two years. Before the end of the two years I tried to update but the website helpfully told me this wasn't needed because there had been no map updates in the past two years. Now a map update is £30. The damned thing is tricky to fire up and counter-intuitive to use.
The lesson is that the manufacturer of the unit is irrelevant. The mapping is.
Having said that, I've used it loads of times in the UK and abroad, in Belgium and France. Not really had a problem, after all, not many roads change and not many motorways are newly-built.
My mate had a Tomtom unit: it was designed to be very easy to use. Designed for people in the US market, who were stupid enough to elect Trump.