What would you do?

Alright here we go...

I'm directionally retarded and have wanted a navigation system for my car for the last couple years- finally got some $$$ for it from some side jobs but blew it on a new car... Also, I've been looking at an MP3 player which I'd use, more often then not, in the car. For the holidays, my family (grandparents, and mother) have agreed to buy one for me, one that I specify, within reason. It seems the going rate for a decent navigation system (external, not indash) is approx 500, while the top rated one is $650 (the TomTom Go). Both my parents and grandparents agreed that they'd spend the extra $$ for the TomTom. Great, perfect. What's the problem?

Due to the fact that I can't go and party during the week (finals), I've been trolling ebay- and've come across the Pioneer AVIC-N1, an in-dash (everything):
-6.5inch screen
-GPS (navi)
-DVD
-Rear view camera (for backing up and whatnot)
-Plays MP3 cd's and shows the ID3 tags, or the title and artist of each song- which basically holds 150 songs per CD
-Measures lateral G's and the performance
... but costs at the very minimum, $1350 (yes, I've checked the whole net)

The reason I'd even consider the Pioneer is that, with my current Valentine 1 and phone charger plugged in, I use ALL of the 12v jack in my car- plus that's 2 wires already. With the TomTom, I'd have to mount it to the dash (another wire), and then, with the MP3 player, I'd have a wire to the CD player (possibly an iTrip, but the reception sucks) and the wire to the 12v- that's 5 wires with 4 external devices!!! The Pioneer is all-in-1.

The only gimmicks I could see myself using with the Pioneer is the MP3 CD player and navigation system- I don't really care about being 'the coolest kid on the block', DVD's don't mean much to me, it'd be installed in my Subaru so performance doesn't matter, and the backup cam is an extra $200 plus installation which would drill a whole in the bumper.

Needless to say, I HIGHLY doubt my parents and grandparents would add the extra $$$ needed to upgrade to the Pioneer- it'd come from my pocket- and seeing that I'm a poor college kid with no steady income, I'd have to reach into a bank account (savings from the summer).

Figure the usability of the technology could be stretched out over the next 4 years:
TomTom @ 700= $175 a year, or $14.58 a month
Pioneer = $325 a year, or $27 a month

The questions:

1. Seeing that I use the whole 12v jack, would I be able to have someone install another one, and how much (approx) would that cost- considering I went to TomTom route?

2. If you were in my shoes, could you justify spending the extra $700 for the Pioneer?

3. What else should I consider?