yes that's true, we must know some mechanism about software /hardware while using laptops or desktops.
service center charges min 300-500 even 1000 rs for small things.
RAM installation is just 5 mins work,remove your back panel and insert ram in correct slot.you can find many guidence videos in youtube and online about your laptop model(if you already purchased ram, so no need 3rd person)
if you are not aware about RAM model,then you can approach service center,they will do the work.