This question is too subjective to answer well, but here's a few things to think over.
A used bike can appear to be in great shape, and still require a large amount of work and money to put right. If you don't know much about the mechanical side of cycling, I always recommend buying new, from a local bike shop you trust, that services their own bikes.
Size is very personal and very specific. Used bikes can fit well, but you need good advice about what fits you, and what doesn't and why. That can be difficult to get from a person selling a bike when they only have one size.
A new, but very basic bike, like the one listed above, can be a very short term purchase, if you get into cycling, and you may need or want to replace it in less than one year. It may be worthwhile to wait a bit longer, save a bit more money, and get a bike which will last you 2-3 years, before you will outgrow it.
Again, I always recommend you buy the best bike that you can afford. You won't regret it, and it makes it more likely you will enjoy the sport.