is it the second cylinder from the timing belt ? it's not that expensive. you are looking at $45 for the parts and half a day labor on the car if u do it yourself. all the rocker arm assembly is gotta go out to replace the gasket
here is like what you have to go thru
valve cover off
rocker arm assembly off
head without rocker arm assembly
it's a pain in the rear and after all the work you need to redo the valve adjustament