Upgrade or not

[Orf]

Hello,
I wanted to know if its worth to upgrade my current rig, its about 3 years old, so wondered is it worth to spend some money or just use for it for like 1 year and buy new one. Im not very big gamer playing just wow, GW2 nothing very fancy, but want smooth gameplay. This is my curerrent rig:

Cooler Master Elite 120 Advance, Mini ITX
MB H87 S1150 MITX/H87I-PLUS ASUS
CPU cooler Scythe Kozuti s. 775/1155/1156/1366/AM2/AM2+/AM3
DDR3 Crucial Ballistix Sport 8GB 1600MHz CL9 1.5V
PSU Corsair CX 430W, 80 Plus Bronze, 120mm
WD Black 3.5'' 1TB SATA3 7200RPM 64MB
SSD Crucial M500 120GB
Intel Core i5-4670S, Quad Core, 3.10GHz, 6MB
ZOTAC GeForce GTX 750 Ti, 2GB DDR5 (128 Bit)

I have very good offer for used Gigabyte GTX970 mini ITX overclocked 4gb, its prety hard to find what could fit to current compact pc case, but wondering if it worth to spend money for this rig. Besides does current PSU have enough power for gtx970 if it worth does the current psu is powerfull enough? Usually i playing playing just wow at 1280x1024 resolution, but probably ill buy new monitor, i want something bigger than 19" so my old vide old card probably will have fps problems with higher resolutions. Guys what you could advise me: to buy gtx 970 or wait some more dont spend money for this pc and buy new rig or may be upgrade something else (different gpu or add more ram)? Beforehand thanks for your help.

[Nellah]

Few unanswered questions here. First, how much are you able to get the 970 for? Second, what would the screen resolution you'd be running? At 1080p or higher you'll see a great performance boost going to the GTX 970, but the GPU isn't worth spending more than about $130 or so IMO since you can get an RX 470/480 for commonly $160 or less brand new and they perform similarly.

Depends in the end on how much disposable income you have and what your timeframe for upgrading a whole PC would be, but your i5 is pretty strong and won't really be worthwhile to upgrade from if the listed games are the main / only ones you play.