*loves teach*
Prices and service of these kinds are slow and expensive in canada, too, but it sounds a bit worse in the US.
Yeah dry ice bubbles pretty rapidly in warm or hotter liquid. Yesterday in my lab the TA forgot to get us ice, so we started using liquid nitrogen and dry ice to cool 800 mL of water lol. It was so clever, and so much faster, too. We eventually had a grad cylinder which we put nitrogen into and dipped into the water, and it worked super well (we needed controlled temp drops of about 3 degrees).
Our data still made no sense afterwards, though, and apparently the relationship between temperature and pressure is parabolic! (nope nope nope nope nope)