GPS 430 or 480?

Just looked at my approach plates. Very few have NDB approaches, some are VOR
DME, some require ADF. More and more now are GPS.
Since I can use the GPS instead of DME for Some VOR approaches, is it not wise
(prudent)
to get an IFR certified GPS now?
Should it be a Garmin 430 or a 480? The cost of the 480 is about 2 grand more,
but I could use it for ILS approaches.
My ADF is useless and I am contemplating a GPS in the place on the panel.
I have never flown a GPS approach.
My finances are low, but my life does have a high value. So says the MRS.
You can email or put your thoughts and suggestion here.
Hank 172 driver