Most fish stores will tell you that.
As someone that got the API test kit and later upgraded to Salifert kits... I don't recommend it? I use the Red Sea Kit for Calc, Alk, and Mag, and I found it to be quite good.
As others have said, the API test kit is just not accurate. I use Salifert, and the 'range' on Salifert for nitrate for example is as precise as 0 to 0.5, 0.5 to 1, etc... Where as the nitrate test kit for API is 0 to 5, 5-10, and 10-20.
I just would hate to see you buy something only to buy a replacement for it later if you don't like it.
To echo the above don't cycle with live fish.
You will find people in the school of thought that its fine. But there is literally no reason or advantage to doing it. It simply doesn't help you. It DOES WORK. Don't get me wrong, it will most certainly work. But -why-? You can accomplish the same thing by 'ghost feeding' (Throwing food in the tank and letting it rot), putting a hunk of shrimp from the supermarket in and letting it rot, or buying pure ammonia and adding a tiny bit until the cycle is complete.
It all accomplishes the same thing. The goal is to start the bacteria culture and have it able to process your ammonia before you put fish in. Otherwise, you are subjecting your fish to ammonia and making them essentially suffer so that your tank is ready. There simply isn't a reason to do it?