40% off at Beretta USA for Labor Day (Code: LABOR40) means a kit is $180 shipped...
https://www.berettausa.com/en-us/beretta-conversion-kit-92-series-10-round-mag-/?OrderItemId=4557772
ETA: The kits with 10 round magazines are $40 cheaper...which is more than the price of a magazine...so I'd get the 10 round kit...