Here are the first week DVD sales for some other TV box sets released over the last few months for comparison:
True Blood, Season 1 - 509,317 units ($19,063,735)
24, Season 7 - 274,496 units ($9,055,623)
Weeds, Season 4 - 178,236 units ($4,454,118)
Family Guy, Volume 7 - 171,966 units ($4,809,008)
Entourage, Season 5 - 167,024 units ($4,052,002)
Stargate Atlantis, Season 5 - 106,161 units ($3,297,361)
Mad Men, Season 2 - 94,774 units ($3,173,981)
Prison Break, Season 4 - 91,232 units ($2,937,670)
Friday Night Lights, Season 3 - 79,182 units ($1,503,666)
The Closer, Season 4 - 70,374 units ($2,077,440)
Psych, Season 3 - 69,279 units ($2,250,875)
Monk, Season 7 - 61,513 units ($1,998,557)
The Shield, Season 7 - 58,594 units ($2,167,392)
Eastbound & Down, Season 1 - 58,586 units ($966,083)
Burn Notice, Season 2 - 57,391 units ($1,835,938)
Pushing Daisies, Season 2 - 52,514 units ($1,139,554)