Upgrade handheld GPS, or save for panel mount?

I am thinking about upgrading my aging Garmin 195. The new inexpensive
WAAS-enabled offerings from Lowrance make it almost irresistible, and my
Garmin is losing value in the used market fast. As I see it, my
options are to upgrade the handheld or just grit my teeth and save up
for a panel-mount. My home airport should have a GPS approach sometime
in the next 2 years, about the same time I will be pursuing an
instrument rating.

The cheapest solution, obviously, is to do nothing and just hold onto
the 195. It works great, if slow, and has a big screen. In 2 years it
will be worthless, so perhaps this isn't the cheapest solution after all.

Right now I could upgrade to the Lowrance 500 for about $100 net, and
have a fancy new GPS with an obstruction database that will be current
for a few years to come. Another option is AnywhereMap, which would
give me WAAS, color, and lots of other features, albeit at a premium,
or---while I'm dreaming---save up for a tablet PC and have the king of
all handheld systems, but I'd need to hold onto my 195 or buy another
handheld to feed it GPS data.

Or, I could start saving for an IFR panel-mount, maybe a used King
89b---I believe the last discussion I heard put the unit plus
installation at around $4500, which is coincidentally about 10x the cost
of the handheld, for a unit similar in speed and function to my old 195
but with a smaller screen. But, I could use it for approaches.

So....

do nothing
net cost: $250 (value of GPS now, dwindling to $100 in 2 years)
upgrade handheld
net cost: $100
sell 195, buy AnywhereMap
net cost: $400
buy tablet, keep GPS
net cost: $2000 or more
panel mount:
net cost: $4500

Am I missing anything?