Is this a good combo

Solution
That 750 Ti is a 1gb model and it has a 6 pin connector in the photo. You'd want a 2gb model that does not require a pci-e connector. For this reason I'd pass on this videocard. The computer is old but i think it'll work as a budget gaming setup.

If that Dell 305W power supply has a 6 pin pci-e connector, I suggest looking for a GTX 650. You can get them in 1gb or 2gb versions. The 2gb would be better if you intend to game at 1080p. If it doesn't have a 6 pin, and my guess is no it doesn't, then you need to look for videocards that run off the motherboard slot power. The 750 Ti would be your best bet but avoid the sketchy ones.
The Tower: This is a very very old tower and will struggle to pay modern games no matter what the GPU is in it. Also this is void of a hard drive and windows so that would add another $150 to the cost.

The Video Card: Despite the 750 ti being 2 generations old the going new retail price is $100. So $65 is in the "too good to be true" category. There are many scamers who take super old nviida cards they get for next to nothing, put a cooler on it and sell them as higher end graphics cards.
 
The tower is old, and the CPU/RAM on it is going to struggle with anything modern. If you can find some cheap DDR 2 ram to flesh it out to 8GB (it's max), have a hard drive laying around and can get Windows on the thing it may be worth it. But it's going to cost some cash to get it up and running. The motherboard should have an OEM key for Vista baked in, so if you can get access to a disk you can load the OS. But any modern OS is going to, again, cost some cash. If you do go for it, make sure to update the BIOS before trying to upgrade the GPU.

The video card should work with the tower. The stock PSU meets the min specs for a 750ti. Now if it's a too good to be true situation like Boosted1G is saying, thats a whole different matter. The only way to know is to roll the dice on it.

 
That 750 Ti is a 1gb model and it has a 6 pin connector in the photo. You'd want a 2gb model that does not require a pci-e connector. For this reason I'd pass on this videocard. The computer is old but i think it'll work as a budget gaming setup.

If that Dell 305W power supply has a 6 pin pci-e connector, I suggest looking for a GTX 650. You can get them in 1gb or 2gb versions. The 2gb would be better if you intend to game at 1080p. If it doesn't have a 6 pin, and my guess is no it doesn't, then you need to look for videocards that run off the motherboard slot power. The 750 Ti would be your best bet but avoid the sketchy ones.
 
Solution


Good catch on the PCIe connector, I completely missed that photo.