It kind of sounds like you're talking about your child and not your partner...

There comes a time in life when we all have to grow up and realise that quick fixes, such as constantly buying bright new shiny toys only fulfills us in the short term. My 20 year old nephew is like this, has to upgrade everything in terms of computers and gaming. Its never enough and I think it just makes him ungrateful and unappreciative (my sister puts money towards this stuff/drives him to the tech stores/waits in line with him).