It IS a necessary repair, but a totally do-able DIY if you can turn a wrench at all.
Usually the rubber valve cover gaskets are OK, but are also cheap to replace if you are not sure.
The valve cover vents are the main leaking area, and are much easier to repair with new RTV if you remove the valve covers to do it.
( you can also clean everything up with gas while you have them off )
There is a stickey here somewhere about this DIY ......