You should probably consider a daily limit (up to some max n days) rather than a hard one time limit. If your engineers can set a 1 and done they can set an n and done and it would be a much better solution and more customer friendly. The guy using 5 gigs today as a poor college student will likely have a position in a small to mid-size company in a few years. I assume non-free (but low tier) customers would much prefer a reasonable limit set as well. Maybe a max of 2x (or so ) bandwidth so no huge surprises. Remember they're your customers and not your paying adversaries