Lifter problems

[amc75]

Hey guys, need some help clarifying something.

My car develops a nasty tick about 1-2 times per month. and usually lasts about 10-15 minutes. Naturally, Lifter tick came to mind, but perhaps it could be the fuel injector. do fuel injectors click or buzz? Sometimes during the ticking, the rpms become a little erratic as if to signify erradic fuel delivery. The ticking always goes away though. Could it be the injectors? Assuming it is not, does anyone out there know approx how much $$$ i am looking at having to spend to replace the lifters? Is there a liquid fix? Could the lifters be replaced by a novice? Also, the tick seems to appear when it's time for an oil change. Once i put oil in, the problem goes away. I've got a '99 saturn sl1 with 80k on it. Any help would be appreciated as the car is at the repair shop now, and i am thinking about just picking it up in the morning and trying a cheaper fix. Thanks!