75DD's are significantly more expensive than traditional 75's which can be picked up cheap if your timing is right and you know where to look.

For what it's worth, you're going to have to import the 75DD's from Dolan in the UK and risk the chance of having to pay customs fees as the major US importer of sugino cranks had an impasse with sugino in regards to the DD's and don't plan on carrying them at the time being.

Also, normal square taper 75's are already overkill for the average rider. External BB, on paper, is the cherry on top.