I've got zero hits on "beer to beer" and "bear to bear" searches, but there are some even funnier "pier to pier" examples out there.
There may be no bears or beers, but we have a couple of, no less interesting, "pee" and "peep" combinations...

Also, the network behind Bitcoin allows pee-to-peer transaction. As a result, an intermediary is unnecessary.
Cryptocurrencies especially Bitcoin were not created to replace fiat. They are even meant to be pee-to-peer currencies unlike fiats.
In other words, peep to peer consist of more work for a trader. Traders don't have much time to sit and talk to the person on the other side of the trade.
ACE is a telegram base peep to peer CryptoCurrency Escrow/Exchange platform ...
...but those guys are making a blockchain peep-to-peer car rental service without the emphasis on luxury.