It depends on what is causing the problem to how much it will cost to fix. If its just the lifter and nothing else, it only a couple buck for the part, but labor is another story.
It sounds like your oil is either to low causing the pump to suck air, to thin, or when your getting on it and the engine gets into the high rpm range and is throwing the oil everywhere, it might be putting air bubbles into the oil and the pump is sucking that up.
That might help explain why it doesnt do it untill the engine is warm, while its cold the oil is thick enough and the pump wont suck air, but when it get warm it gets thin and flows easier and it can get away from the pump easier causing the pump to suck air.
If your pump sucks oil then when that air reaches the lifters it would cause them to fill with air and then that would cause a ticking noise, but unless your loosing oil pressure constantly, the noise should go away quickly, untill the pump sucks air again.
If they weren’t meant to be eaten, then why are they made of meat?