Part of the problem here is the price of a used graphics card seems to level out once it falls below $100. For right around $100 you can find cards like the GTX 970, 3gb GTX 1060, RX 480, RX 580. Sometimes you can find a good deal on craigslist, but those are few and far between. ebay is a more reliable place to...
Best answer: Part of the problem here is the price of a used graphics card seems to level out once it falls below $100. For right around $100 you can find cards like the GTX 970, 3gb GTX 1060, RX 480, RX 580. Sometimes you can find a good deal on craigslist, but those are few and far between. ebay is a more reliable place to find a used Graphics card.
If you're running a GT 440 then you most likely don't have a good power supply. Does your 450w power supply have an additional 6-pin PCI-E connector? Typically a 450w power supply that does not have this connector is false advertising, and this will have trouble with a GPU, even if you use the molex to 6-pin adapter.
#2 which is the GTX 750ti would be a decent pick. Although, the GTX 750ti is over the hill and it will have trouble with some of these new games. The GTX 750ti is a funny card because it's based on the Maxwell architecture that is behind the 900 series. The GTX 750ti is as powerful as a GTX 560ti or the GTX 650ti version with +1000mhz core clock.
The GTX 650 should be scratched off the list.
The caveat with the GTX 960 is it's as powerful as a GTX 1050ti, but it consumes the same amount of power as the GTX 1060. At least a GTX 1050ti and the GTX 1050 will work with a decent 300w power supply. The GTX 760 falls between the GTX 960 and the 950.
In all honesty I would recommend taking a look at an RX 560 or RX 570 before I would recommend any of those cards you listed. The only caveat here is some of those RX 580 and RX 570 cards were used in mining rigs for a short while. The problem with buying one is you'd have to make sure it has the original BIOS and not a modded BIOS. The RX 560 was not a popular card for mining.
You can also get a 3gb GTX 1060 on ebay for around $120, and that's probably one of the best deals you're going to find. To sum this up, I recommend spending an extra $20 on a 3gb GTX 1060.
-The 3gb GTX 1060 is 60% faster than a GTX 960
-The GTX 1060, either 3gb or 6gb, only consume 110-130w while gaming. In which case this should work fine with your 450w power supply.
-The 3gb GTX 1060 should be fine with your old Sandy Bridge i5 CPU. The bottlenecks would be slight but nothing extreme or bad. If there is a bottleneck with the CPU, it's the game engine, not so much the card, and this would vary based off the game's engine and settings.
-Driver support for 600-series and 700-series Kepler cards is awful. 900 series card will suffer the same fate soon. The 10 series should have the most longevity for driver support.