[Solved] Upgrade from Radeon HD 4850, go big or hold off?

So my Radeon HD 4850 512MB RAM video card just got fried when my PSU crapped the bed.

I have a 5 year old machine:
mobo: ASUS P5ND2-SLI
RAM: 4GB DDR2 667MHz
CPU: Pentium D 930 (dual core: 3.0 GHz) 800MHz FSB
GPU: the late Radeon HD 4850 512MB GDDR3 RAM

So clearly I could use an upgrade of some form. I just replaced my PSU with a nice 850 watt Corsair AX850 professional series only to find that my GPU had gone out the window with my PSU.

So my question is this:
Do I replace my 4850 with something comparable, or maybe something even a bit worse like the GeForce GT 430 and stay under the $100 price point to get me through another year or two before upgrading my system? Or should I just splurge on a nice card now and upgrade my system within the year? (Also, I'm just assuming my mobo can support current cards since it has a PCI-E x16 slot, is that a safe assumption?)

That being said, what cards are comparable to the 4850 that won't run me more than $100? I am kind of leaning towards the cheap way out of this given the holidays have taken their toll.

Thanks much, all advice is appreciated.

Hold off and replace the rest of the machine.
Sell the DDr2 cause it is pricey now
throw the rest in a media/mom PC

No it wouldn't.