ElTerprise: Hello Crow. Yes. I already "own" Borderlands 1 GOTY and Borderlands 2 GOTY and all of those B2 DLC really confuse me. But 75% off the Pre-Sequel is actually quite nice though....
Edit: But i'm curious if Borderlands 1 will be edited for germans...
Well, since you have the GOTY version, everything offered would be redundant aside from the 5 Headhunter DLC's and the Vault Hunter Upgrade Pack 2.
Retail on those items is 20 dollars, so you'd save 5 in total and end up with a code for the 1 dollar tier that you could give to someone else, since everything is bundled by tier level.
Also, it's looking like censorship is in place since it says at the bottom of the page that German users get an edited version.
The only way to save serious money would be if you use the coupon for the pre-sequel (such an idiotic title) and save 45 dollars on retail.