LOL; I understand what you're saying here...but before I "just do it" I need to make sure we can really afford it, so that's why I'm asking opinions regarding the impact differences.Yes, the impact will be greater.
Here's another way to look at it:
If you get the 58", you'll never say to yourself "should have stuck with the 50 inch". If you don't get the 58", you'll constantly be saying "I should have got the 58 inch".
So, just do it.