Join Date: Jun 2008
Location: New York, NY, USA
I don't know the specific type of plastic used for the cases, but have had lots of success repairing plastic like that used in car bumpers. etc using repair adhesives designed for just that. Your damage does not appear to bad, maybe you could try the repair route on those cracks, etc. I have also heard of 'welding' procedures on plastic. This might be worth investing less than say $100 before buying new. If it works great you saved $300+, if not go for the new part.
You might also want to check with someone like beemerboneyard (google them), ebay and the like (I'm sure those here have other sources too) to see if they have the parts, cheaper than new.
2008 K1200GT, Custom Paint, Vivid Black, Aeroflow WS & Aeroguards, Givi E52 Maxia Topcase w/AdMore Lighting, Zumo 660, Suburban Footpeg Lowering, Sargent Seat
2009 R1200GS Adventure, Magnesium Grey/Black, Adventure Cases, Zumo 660, Touratech Unobtanium Accessories
1974 Norton Commando 850 Soon to be a restoration project