When it is time for a new computer do you go with a used model or a brand new one? The experts will tell you that first you should know what you will do with the computer. Are you using it for work? For high end gaming? For checking social media accounts and emailing? Because computers get more and more powerful all the time something that is a few years old just won't be able to compete with something brand new unless you don't need or anticipate needing it for anything full on fancy.
Old computers are behind in a lot of things, the operating system is a big one. While the new ones will have the latest OS on board, the older ones won't and if you get a computer that no longer updates then you could be in trouble.
Another thing to consider when getting an old computer is what will you need to buy to make it work the way you want? Will it need a new battery? Will you need peripherals? What do all these things cost? Maybe getting new is the way to go. You can use it out the box, it has all the latest and greatest features and you won't be spending more for add ons (unless of course you want to).
If you do go with a used machine make sure you check it over well for damage. This means are there cracks? Is there a haze on the screen? Are the ports in good shape? You should also be cognizant about the keyboard, does it work? Are there missing keys? How does the trackpad work? And of course does this used machine come with any software that works or are you on your own? Will it need upgrading the minute you try to turn it on?
Basically, know what you are buying. Do your homework. Look up what comparable models are selling for on online stores and resale sites. Look to see what original owners liked and disliked about a certain model and when all else fails, look for a new one within your budget.
Of course new computers have some problems of their own, but they will have a warranty and other things to protect you should you need work done on your unit within a certain time frame. Getting used to a new operating system may take time, but it may be worth it in the long run.