Q: Erratic Trackpad Issues. MBP/R Late 2012

I got this Macbook a year and a half ago, November 2012, and within a month I spilled an entire bottle of watter all over the thing. But luckily, I was quick about it. I shut it off immediately, and threw it upsidedown in a box of rice for a week. I took it out and no harm done. It was perfectly fine. I never experienced any issues with it.

2 years later. I take a damp clorox wipe to my keyboard / trackpad, as I have many other times. I have oily hands I guess. I like to keep things clean.  I probably should have shut it off, but I didn't. I hit a few buttons when I wiped off my keyboard.

10--20 minutes later, my trackpad starts having a seizure. Clicking things. Creating folders, renaming stuff on my desktop, swiping across my desktops. Insane things. Even typing a letter or number here and there.

I tried restarting it and I got a weird graphical glitch when the gray apple screen came up. There were some weird colors and that really worried me.

I was worried about liquid getting under the trackpad, and it probably did, but not much. I mean I spilled an entire bottle over the trackpad area and it was fine, It'd be completely insane that a quick damp wipe would have ruined it. But I shut if off and left it in a box of rice for a day.

I took it out and it worked fine... for 30 seconds, before it gradually started to get worse.

I boot into Windows 8. Exact same problem. So it's deffinitely a hardware issue.

Boot back into OSX and after fighting with the erractic behavior I somehow managed to get into the Accessibility preferences to disable the trackpad when a wireless mouse is connected. When I did that, it stopped, and I finally got control back and now I'm posting this.

I tried resetting NVRAM/PRAM but that didn't do anything.

I don't have warranty or apple care anymore, and maybe I shoud, considering all the issues I've had. I guess, does anyone know how much it would cost to get this fixed? The drive to the Apple Store is pretty far for me. Is it even worth it to have it fixed? Could I fix it myself ordering parts?

I've also had a buzzing left fan for a while. It still keeps my laptop cool, according to iStat Menus, but I'm thinking it's about to die.

2 years seems kind of quick to buy a whole new laptop, but if the price to fix the fan and the trackpad is over $500, maybe I'll just sell this one as a parts laptop on ebay for $1000 which is less than half of what I paid and use that to get a new one.