Honestly the fact you can pull 49 times off something that requires a pseudo currency is pretty nice.
It's difficult to equate it to an SG saving because it's not like they set the odds without any awareness that players could get up to 49 free scratches, and if the odds were better it's not necessarily as much of a saving because you'd have to account for the greater chance of the player getting the item within fewer scratches. I don't much care to do the maths on that but it's something to consider.
The free scratch mechanic is great for encouraging players to check in regularly and keep player retention and engagement. I think it'd have been better still if it counted towards the choice ticket (since that would be extra incentive still to log in at least 40 of 49 days on top of giving the feeling of being more generous) but it's still something and I think a good thing.