There are a couple of errors in this file. They are not related each to other.
1. 12 & 13 use EntityQuery class that is not available in these releases. This cause error in Quick Add screen creating a purchase order.
2. In all releases the code in that file try to collect prices for variants. Doing so it use NumberFormat.format() to transform base price into string that is part of an embed JS snippet. In case purchase order this price is rather empty. Using null with formatting method cause error.
You may see this error in the trunk if you starts PO and and try Browser Categories->Widgets->Small Widgets. This price should appear if you select Select Units of Measure for WG-1111 but currently this does not work.
I'm not sure these prices make sense for purchase orders but my goal was just fix ugly error message. Solution display N/A if price is not available.