Sure it's never bad to have a diagnostic tool.
I have an Autel MOT Pro EU908 approximate since ten years. It has lifetime software updates of all cars worldwide.
You can read all errors you can see live data, you can reset oil Service and open Park Brakes at newer cars.
I'm very satisfied, I had only a few cars which I could not read proper.
I would look for something used, if I were you, for example like this:
Entdecken Sie Autel MOT Pro EU908 All System Diagnostics Multi Function Scanner EFB, Oil, DPF in der groÃen Auswahl bei eBay. Kostenlose Lieferung für viele Artikel!
www.ebay.de