Severe ticking noise
 

Ticking sound coming from the left side of the engine, away from the belts. SES light is on (have not read the code yet) temperature gauge functioning normally showing standard levels, not really noticing a loss in power. Other than that my turn signal has been crapping out (despite changing the bulb all the time) I have noticed some things that make me question the alternator, but that wouldnt cause ticking right?...the car is an 02 with 150k mi.

The turn signal issue is unrelated to the ticking. It is important to read the code as that might lead you to the problem rather than speculating. Does it sound like a valve tick? A bad bearing in the alternator could cause a ticking sound. Need more information on what the ticking sounds like.

Ok so I got the codes read-
P0171
P 300
P0442
So it's misfiring...they said it could be a lifter, or cracked piston or head gasket. Not really sure what to do at this point.

I'd suggest a compression test.

If it is a lifter, what are my options? How much $ am I looking at?

You are getting P0300, that is general misfire. If it is a lifter causing misfire it would be specific to that cylinder. You need to determine where in the engine the noise is.

You are likely looking at removing the heads
 

First course of action is to do a compression test to see if one of your cylinders (or more than one) is not holding pressure. More than likely if you have some sort of loud ticking you have a problem that is going to require at a minimum the removal of the valve covers for a good inspection, and if low compression likely removal of heads for at a minimum gasket replacement.

The back of the engine is a PIA to get to. I actually took my venture into a shop to diagnose as weird shining noise and small leak that I could feel was wetting the firewall and creating steam on very cold days here in texas. they said sell the car... the whining was a pully $15 and the leak was a pin hole in a rear heater hose that was nearly impossible to see, and was a pain to replace. THE secret to working on the venture IMO is knowing to remove the front engine stabilizers to turn the entire engine forward to gain access to rear of engine.

IF you have compression issues you could try the fix in a bottle, but usually if it works (and it can for small head gasket failures) the fix is temporary and will eventually fail. You may have good compression and then your problem is likely in the valve/ lifters/push rod/ rocker arm arena for the loud clicking.