Ray Andraka wrote:

I think it is a 'whole enchilada' thing. If you are spending the money
to replace anyway, it might be worth considering spending a little more
to put in added capability that you might find yourself needing sometime
in the future. In the case where you do end up needing to sell, the
relatively small delta cost to get more capability that you might or
might not use now might be worth it when it comes time to sell. Think
of it as the delta for the GPS install, not the full cost, if you are
already replacing a radio.

If I were replacing my airplane today, I also would not consider one
without an IFR GPS. On the other hand, I'm not rushing out to replace
my servicable dual VOR, dual glideslope and Loran stack with a GPS unit.
I'll strongly consider it when the time comes that my radios break and
are not economically repairable, however. If it happened today, I'd
probably hold off on a GPS upgrade to see how the next gen ATC falls
out, as I'd hate to have to change out new to me equipment to meet new
equipment requirements such as ADSB in a few years.

You use words like "a little more." You also state if it was you you
would hold out. But you are also in the same post trying to suggest my
comments are off base?

This makes sense if the marginal cost difference was a couple grand, but
we're talking 5 to 7 times the cost to replace it - not just a little
bit of money! A delta of 10% to even 100% is reasonable, but come on, 5
to 7 times the amount? That's ludicrous. When the plane MAY be sold
later on, that piece of avionics that cost 12k or more to put in, will
net negative dollars and will not be the latest and greatest thing that
everyone is looking for.

People look for those radios already in the plane because they know they
are getting a bargain on the installation. So, you are advocating the
owner in this case to be a sucker so all those shopping for his plane in
the future can take advantage of his already spending waaay too much
money and giving him zip in return.

This is the part that I have trouble with. It is plain old bad advice.
Now, if the OP said he was looking to get a GPS in the first place,
then I think the advic is right. But he did not say that.

Jay Honeck and a few others had good advice. Replacement slide in.
Going with a 12k radio just because other people like it is ridiculous.