Microsoft Windows 7 Home Premium Upgrade Family Pack (3-User) for $149.99 shipped.  This family pack is generally hard to find nowadays.  Here is a screenshot for your reference.  Note that both 32-bit and 64-bit versions are included.  This provides Windows 7 upgrade for 3 PCs that have either Windows Vista or Windows XP.  This is a good deal for a multi-PC household as a single upgrade is usually about $109 so doing upgrade for 3 PCs would normally works out to be over $300 (3 x $109).