The retro-ones are very good, but I find them ugly as well.
I would give it a second try. With a bit of patience you'll find a Becker for under 300 inc shipping. But, ya gotta go to ebay.de for more choice and select "shipping to germany". You can always discuss terms with the seller after he's sure to get paid. Ebay.com has the highest prices, not a great place for W116 parts, and also not for a whole range of items.
Also, check out that "rebuilt" idea. Rebuilding/updating the beckers would be the best way, I'd think.
Don't forget.. if you drive that w116 for a while, you'll end up putting money in. The more you invest, the more you're investing in resale-value.
When that day comes, an original dash is a plus.
If you want more options, you can install a second headset, hide it somewhere, and use the remote to control it