Might be ok with polys. Other fish will be an issue. That’s why I request for fish to be individually bagged if able.Personally i dont like two days shipping, fish have more chances to become unhealhty before you get it, you can have ammonia burn, that can cause alot of harmful stuff to the fish.
Then you’ll endup buying meds to cure the fish that will cost more than the $30. Another thing is the amount of oxygen in the bag, we wont know how much they will use, then how cold will the water get in the bag.
If you bought from them before and know how they ship its up to you.