I've been reloading 16ga since about 1970
First, make sure you can find 16 ga wads in your vicinity. Of course, you can always order them and pay shipping. Either way, make sure you can get wads easily.
Second, bags of shot are now almost as costly as loaded ammo. Currently it costs me about $3.58 for shot and $2.06 for wads and powder and primers to load 25 shotshells in 16 gauge. You won't get cheap ammo, but you'll get ammo when you need it.
New or used, shotshell presses are inexpensive compared to metallic. Go check out a few before making your choice.
Shotshell reloading works best with premium hulls, like AA or STS Premier. But you can reload plain old field hulls. Just be prepared to be innovative because very little load data is available for cheap field hulls, which differ considerably from premium hulls in critical areas (like the shape of the base wad, for instance). Learning about patterning and a chrono may be useful.