First off, yes the GT 630 is on the same range as the 9800 GSO.
However, this particular 2GB GT630 version should be a Kepler one.
Specs looking not very promising. Even if it's newer as the 9800GSO, the specs are even worse as your 9800GSO.
It has a very low Texture Fill Rate and Memory Bandwidth as well.
9800 GSO -> TFR: 26.4 - MB: 36.4 (192 bit)
GT 630 -> TFR: 14.4 - MB: 14.4 (64 bit)
I thing on the same settings (mid-high), you will be forced to lower your resolution a bit.
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Well, you are not going to get a "fine" graphics card for under $50.
An okay graphics card where you can play most of the modern games at mid settings would be around $100.
However, I would consider this one, almost in your price range:
http://www.amazon.com/XFX-Radeon-HD6670-PCI-Express-HD667XZHF3/dp/B004Z5GRW6/ref=sr_1_5?ie=UTF8&qid=1426971866&sr=8-5&keywords=HD+6570+1GB+DDR3
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As for the error, well it could be hardware related but software related as well.
So as Níeh?ggr said above, try to uninstall anything related to Nvidia from your Control Panel.
This as well, if you have problems to boot into Windows. [ Try booting into Safe Mode, if a normal boot doesn't work. ]
Also run Ccleaner after that. Go to the Registry panel o the left, and press: [ Scan for Issues ] LINK: http://www.filehippo.com/download_ccleaner
What's your Operating system, and is it 32 bit or 64 bit ???