Here is a different way to look at the problem.

How bad of an investment do you want to make?

1. Installation is lost the second you put the machine in the plane.
2. The value of the box is already depreciated.

Considering 1 and 2, the more you spend on the box, the better the
investment. For example, if installation is 50% of the cost, then you lost
50%. If installation is 25% of the cost, you lost 25%.

You have a basic 172N that likely has another decade worth of service left
in it before it starts to go south on value. Why not buy something that will
last that long?

Unless you can get a sweet deal on the install, or on a particular unit, I
would be slow to dismiss a nicer machine like a used 430. Even if you spend
3k more, you will likely get it back. And, if you decide to sell your plane,
you can count on moving it much more quickly with that box in the panel.


"C Kingsbury" wrote in message
ink.net...
Hi all,

Currently examining options for upgrading a 1979 172N with an
IFR-certified
GPS. We currently have two good nav/coms, M-1 Loran, and ADF that we want
to
replace.

Goal is to find the most cost-efficient IFR GPS install to replace the ADF
and add legal /G and DME capabilities. Keeping in mind that the plane is
worth maybe 50k we are not going to spend 10-12k on a GNS-430 class box,
so
as I see it we have these options:

- Northstar M-3 Approach
- Garmin 155 or 155XL
- King KLN-89B or KLN-90B
- Apollo GX-50

AFAICT one can pick up a decent used example of any of these for between
$1500 and $3000 depending. I know we'll also need the annunciator and CDI,
and that installation/certification will comprise 50% of the total cost.

One of my big concerns in buying an older GPS is database updates. I want
to
make sure we will not end up say a year or two down the road with an
expensive VFR GPS because updates are no longer available. Also, general
mfr. support.

I would like a decent moving-map capability, but given that we have none
in
the plane right now, even a simple airspace depiction like the KLN-89B
would
be a significant gain. If we want something snazzy we can get it better on
a
handheld anyway. I would spend an extra $500 for a better map, but $1000
or
$1500 I'd wonder about.

What would you guys do?

Best,
-cwk.