I've done a bit of math:
Lets set B as the number of base items needed, so a lv. 1 item is worth 1B, a lv. 2 item is worth 2B ... and a lv 6 item is worth 32B.
Then 5 coins will give you an expected value of 3,82B. And a lucky draw is worth 23,485B, assuming that these draw chances are correct...