If it is a great PC game with a lot of great levels, fun gameplay, good plot, cool mods, and is fun to replay, I would buy a PC game which require 200GB of space to install on a PC's hard drive.
But, I have to buy it in Blu-Ray disc format because my internet service provider has a 150GB download limit. It also will take a long time to download 200GB of data on a 15 mbps internet connection.
I think future versions of Grand Theft Auto, Call of Duty, and Crysis games for PC may eventually become 200GB in size because game cutscenes and gameplay video for future PC games will need to look great on 4K monitors, and faster Gaming video cards which are becoming more popular with PC Gamers.
From what I can find, the biggest game to date is X-Plane 9 which clocks in at 70-90 GB for install size. But when we start hitting 4k standard and higher, oh yeah, games are going to be hitting the hundreds easily. This will take things back to the CD age or the ISP is going to have to change standards.
I think most very big file size PC games will be recorded on many Blu-Ray disc once they are 100-200 GB instead of DVD disc which is the most popular format for recording PC software to because of the low price of DVD disc, and most PC users own DVD-ROM drives on their desktop, and regular sized Windows Laptop.
Some uncompressed audio like FLAC recorded for surround sound speaker system can use a lot of storage space like 4K.
I think disc based PC games are a good idea, but the game makers made owning disc games annoying by requiring users to put in a registration serial key which is super long, and did not allow people to easily make backup disc copies of their games because it was copy protected.
It depends if it was a game that interested me. If it was something that I really wanted to play, then yeah, I would buy it, even if I had to leave my PC on overnight to download it.