The 4 DLC packs (more maps & variants) for the PC & Mac version of Ticket to Ride on sale again. Last time I posted (end of Feb), it was $2.99 for just the base game. Now, the "Upgrade Pack" is on sale for those of us that already have the base game. The "Complete Pack" is available as well.
My Woot! link to the Complete Pack: http://deals.woot.com/deals/details/21493acf-2a84-4f92-8b44-fe4769b67521/ticket-to-ride-complete-pack-pc-download-video-games
Regular pricing is $14.96 combined total for the 4 DLC's.
This is sold as a Steam key and requires a Steam account to use/download/play. You get an individual code for each of the 4 expansions.