How to Join values from a reference sheet based on selections in a multi-select dropdown

Based on preliminary searching, it seems this may be impossible, but I am hoping to use values chosen from a multi-select dropdown to collect and join values associated with each dropdown in a single cell.

In this example, a donation manager is choosing donation items from a dropdown with over 40 selections. In the column next to it we want to collect the associated dollar values that correspond with each item.

Here is a very small example of the data source:

And here is where I am wanting to pull in the "Item - Value" column:

In an ideal scenario, the "Item Value" column would read: "Team Autographed Basketball - $4000, Autographed Jersey - $1200"

Let me know if there is any workaround here. I can't add any helper columns because the list is too long and the items change on a regular basis depending on who is currently on the team.