Here’s a quick tip for tonight.
These days, a lot of computer come with a sufficient slab of RAM installed (and I’d be recommending at least 4GB of RAM these days and 8GB of RAM on 64-bit systems to cater for growth). Sometimes, a computer will come with a lower amount of RAM preinstalled and you may be given the option to upgrade the RAM by the retailer.
Whilst this option may be convenient for you it may not necessarily be the best deal for you. Some retailers will charge multiple times the standard cost of RAM for any increase over and above the base configuration despite using commonly available RAM available in the market. Furthermore, you might not get the choice of RAM in your computer which can be a big deal for some people.
In order to get the best deal, I would recommend doing some research on the price of compatible RAM for your computer. For those used to building computers this should be a fairly straightforward exercise but for everyone else you might want to enlist the help of a friendly nerd. If you’re really nice, not only might they recommend where to get more RAM from and the cost but also to install it for you (just make sure you look after them).
Don’t forget, if you buy your own RAM your warranty and support will be provided by the place of purchase and not the place where you bought your computer (unless it is the same place of course).