Looking to install my 898. Round about number on cost of installation? Any rookie mistakes to avoid? A little nervous after reading through all the posts on different problems. Do I need to update my 898 unit even if it is brand new? Also, wondering about my Navionics Premium chip from 2 years ago that was updated last spring. Sorry I am a newbie!

For the install, if you cannot do it yourself, get someone to do it that is familiar with imaging sonar units and the proper transducer mounting for that technology.

You don't know how long the unit has been in a dealer's stock, so it might not have the most recent software. Updating is easy and quick.

Yes, your Navionics will work in the unit.

Additional info will be sent via message.

Remember, the best, most common types of installations, particularly the transducer, can produce miserable sounding results, not to mention damage to your boat. In fact, transducer installation comprise the majority of all marines electroncs toubleshooting issues. And, it's a very good idea to become very familiar with with your boat warranty prior to installing anything in a "vulnerable" area, such as below the waterline. Because...when your transducer isn't up to par, no one is.
Safe boating...

I have several Help Videos on Installation of Humminbird on YouTube that should help: http://www.youtube.com/playlist?list=PLFBA73CD339FC6B95