There's nothing preventing you from buying multiple dice though....totally legal, and totally against the spirit of the rules IMO. Really getting close to the "bag of rats" rule
What.
"Bag of rats" was a cute way of twisting badly worded in game things to create hilarious and unintended results.
This is just buying a magic item more then once.
Buying something more then once is not against the spirit of anything. It's simply spending your money on something again.