I have a $0 + taxes & fees inside cabin casino offer, did not upgrade and was able to add on HIA for $50 by calling. It’s the base HIA I think, crew gratuity not included and the low level drinks and internet.
I was able to add it by calling. Internet said not eligible, I felt their were 2 phone tree selections that might work, 1st one the person said not eligible, 2nd time through I did the other and they got it added no issues a few months back.