I was hoping that someone else would make a more indepth analysis of the situation but since I haven't seen one here's my attempt.
If we are going to do some maths, we could start with more accurate figures.
Watchtower
December (last of the monthly editions of the public version) Public edition report 52,946,000 printed for Dec (which I believe includes all editions including the study edition
Public edition "available February" (No. 1) reported 58,987,000 published
The Watchtower study editions do not include the numbers printed, therefore the number of the January editions printed cannot be ascertained. Therefore I am assuming that the increase of just under 6,000,000 copies between the numbers given in the December public magazine and the No. 1 February magazine would be for the study edition of January.
Awake
December edition reported 51,768,000 printed and was monthly at the time of this print
"Available January" edition (No. 1) reported 57,761,000 published and this was the first edition to be printed every two months
Therefore
Approx 53,000,000 - 6,000,000 = 47,000,000 by 6 months less Watchtowers being printed each year
Approx 52,000,000 - 6,000,000 = 46,000,000 by 6 months less Awakes being printed each year
Average out both mags to 46,500,000 by 12 months less mags printed each year. At .10cents (I think they would cost more to print but have not idea how much) a copy thats $4,650,000 x 12 months =
$55,800,000 per year savings.
The two biggest assumptions here are the cost of printing each magazine and their change in wording from printing to publishing being treated as meaning the same thing. Knowing the WTBTS they play around with words to give an impression to mean the same when they don't. The change to using 'publishing' probably means that they are not printing the amount published but have accounted for a certain amount to be accessible online, my guess would be that since they aren't sending mags to India anymore they have included the number the would normally print for this country in the published figures.
Feel free to make any corrections.