Instruct: Classify the given review into positive or negative sentiment.
Query: Inexpensive, accurate, and upgradable

I purchased a used Magellan Explorist 400. The battery had shorted and I could only use it with external power. I purchased a new battery and go the unit to work perfectly. The MapSend Top, Direct route, and Blue Nav XL-3 charts work great on the unit and are inexpensive on Amazon.com. The Magellan support site has very recent updates for the GPS Wass enabled satellites and for the unit firmware. If you want the most recent maps then you will pay a lot for the software but if you settle for the 1-3 year old maps the software available on amazon is great. The unit lacks a speaker, Headphone plug in, Blue-tooth, being that is a discontinued GPS line.... that is expected. In conclusion this is a perfect starter GPS because it can be expanded and the older software is still available.