I have seen successful tanks using southdown sand. Although it ends up looking super compact and its quite unappealing in my opinion.
The play sand that I have seen has particle sizes of salt grains or smaller and looks a lot like mud after awhile. This may have been this particular sand and a poor example. You may want to have people post pictures of sand beds using this method and seeing if you like it or not.
There is nothing worse than getting it in there, having algae problems and it look nasty then having the trouble of removing it all.
Not sure if you are looking for other advice, if not, ignore below:
I ended up doing a sand bed that is less than and inch using dry carbisand type product. This was inexpensive and is still a very effective sandbed in my opinon, since it is so shallow I have no real risk of a major stir up causing a nitrate or ammonia spike as a DSB would have.
Marinedepot has some 40lb bags of sand for a very nice price. Have them ship this to your door and you will be much more pleased with a nice, clean, white sandbed where you can actually see the particles. It looks so much more realistic.