unable to use artifacts on all my characters

i noticed only 1 of my characters has access to artifact usage. when i checked my cartel coin purchase history, i saw where i purchased an unlock for 1300 coins. When i checked the store in game the same unlock is for 1400 coins. i am unsure if there was a price increase and there is no option to purchase that unlock for a single character, only for the whole account. was there an error when i first purchased it?