Check car-part.com. You may get lucky and find a 2009-2010 Vibe and / or 2009-2014 Matrix in a junkyard near you that you could grab the cup holder inserts from for cheap.
2009 Liquid Platinum Metallic Vibe GT - 5-Speed Auto – Garage
2009 Steel Blue Metallic Vibe GT - 5-Speed Auto – Garage