I want to minimize cost when I enchant and I've already lost 2 daedric items because I believe I didn't use the proper gem. Most likely I use the black star or a grand soul gem filled with a grand soul but most likely I'm looking at the price of the gem. A grand soul gem filled with a petty soul is pretty affordable. My situation is that I have 2 steel armor with a 17,5% more enchantment then on the daedric armor. Hence looking at the price of the black star it is usually 1000 septimes but a grand soul is 500 septimes.
Is the black star better filled? Is there are better bigger soul then grand soul gem filled with a grand soul worth a 500 septimes?