So here's the thing, IMHO...you really have to ask yourself, in $$$ terms, how much your time and trouble is worth. Then ask yourself whether the extra time/inconvenience involved in cutting down boxes to hit that USPS 108" max is worth it. Remembering that you have to make sure the frame is protected well enough despite having less room for padding, make sure you've re-taped/re-stapled all the sides/flaps/corners you cut. Remember you're not just shipping it a lot further, the box will likely get handled/transferred more---and you are responsible for any shipping damage.

If it takes you 90min to prep/pack for domestic shipment, but twice as long for int'l via USPS, what's that extra time and effort worth to you? Will the international customer pay more money for the item? Could you sell it just as easily in the US without offering int'l shipping? Could you charge $25-$50 less without shipping int'l, saving yourself the extra time/effort?

There's no right/wrong answer here, you just might want to think this all the way through before you agree to ship this thing to Germany for $95.

I'm not shipping a lot of bikes/frames these days, but probably at least 70 over the past 10yrs. I'm pretty good with a box cutter, I liberally use my industrial box stapler, and I generally do not ship bikes/frames/wheels internationally. Just not worth the extra time/trouble for me.

And forgive me for sounding like a crotchety old jaded seller, but any potential buyer trying to tell me what my shipping costs should be, and how big a box I should be able to fit my item into, is somebody I ain't selling to. This one kinda smells like trouble to me.