Is the 2500K still worth getting?

I know it's an older processor but at ~$150 at my local microcenter is it worth it over the 3570k. If I'm mostly gaming.

It's definitely worth it. The only real advantage to going with a 3570K is the PCI-E 3.0 support, which isn't necessary right now anyway.

Yes. Just like Vortex says. The 2500K will also run a bit cooler then the 3570K

doesn't sandy bridge oc better than ivy or am i mistaken?

It does overclock better in general, but it's only by about 200 - 400 mhz more. It depends on the chip you get. Generally, sandybridge is capable of doing between 4.8ghz and 5.2ghz, while ivy is generally capable of doing between 4.6ghz and 5ghz. It depends on your cooling setup and your individual chip. My 2600K is only at 4.6Ghz right now, but I think that might be because my RAM is at 1.65V. I'm going to be getting some new RAM and a custom water loop in the future just to see how far I can push it.

So, with a asrock extreme 4-m (micro atx) and a h80, how far could I push the 2500k?

I don't know, but the H80 is overpriced and overrated. You would be better off getting an NZXT Kraken X40 or Phanteks PH-TC14PE.

Only problem with the Kraken x40 is the only place to mount a radiator is 120mm. I guess I could go air but is there a 120mm closed loop water cooler you would recommend that can outperform the phankteks you mentioned or anything similar?

THe case I got is a Silverstone sg09b.

its cheep on newegg right now but i always say use whats in the now, you will thank yourself in the future. go with the 3500k or an AMD 8350 for around the same price. 

The large double tower coolers are going to outperform most closed loop systems. The Phanteks PH-TC14PE, Noctua NH-D14, and Thermaltake Silver Arrow are all going to outperform the H80. The H100 is about on par with those coolers, the H100i should perform slightly better, and the Kraken X60 will perform better. Those are really the only closed loop systems that will outperform them though.