Green Man Gaming offers downloads of the Total War Master Collection for Windows
for $22.49. Coupon code "GMG20-ODON7-FLUA7" cuts it to $18
. That's tied with our August mention and the lowest price we could find by $72. It includes Medieval II: Total War, Rome: Total War, Empire: Total War, Napoleon: Total War, Total War: SHOGUN 2, Viking: Battle for Asgard, and Total War Battles: SHOGUN.
Also available is the Total War Grandmaster Collection for Windows for $33 via the above coupon code. That's tied with our April mention and a price low of $132. It includes the seven games above plus applicable downloadable content.
Note that these games require a Steam account to play.