Ya but many games these days need to be updated before playing to the latest version which downloads the whole game anyways, isn't it?
Yes, but at least with new games, the update sizes are much more reasonable. For Rome 2 Total War it was 2GB of updates. For AC4:BF, it was about 1.5GB. So the updates are about 10-20% of the size of total downloads. If you have an internet connection with 15-20GB of FUP, you can get the updates easily, but getting a full game or two will take you above the limit.
Max Payne 3 was the biggest culprit - 27GB of download!!!