A wooden sandbox is typically placed in an outdoor setting. Since it's exposed to the elements, you also need to consider the durability.
Another factor that you need to be aware of is that there's a correlation between durability and cost. This means that the more durable the sandbox becomes, the more expensive it will be. This article is not saying that you should always buy the most durable. Rather, find the right one that fits well into your budget, and can serve its purpose.
If you want something that is fairly durable and not very expensive, then a wood sandbox with a cover made from solid softwood is advisable. On the other hand, if you want something that is very durable and the cost is not a big issue, then a sandpit that is crafted from solid hardwood may be the choice for you.
A sandpit made from manufactured wood is usually very cheap, but it's not advisable because they don't last very long.
Another thing to check is the hardware. Stainless steel nails and/or screws may be a bit costly, but they are usually worth the money.