The only items TPIR gets promo fees from are sponsored groceries & small prizes. Before they switched to cash for Contestants Not Appearing on Stage, I believe some (all?) consolation prizes were part of that arrangement as well. Roger has said on FB that near the end of Bob's run, it was $1,000-$1,200/plug, which naturally helped their budget quite a bit.
My understanding of the modern arrangement on other prizes is 1 prize = 1 plug. So if Broyhill supplies a dining room set, that dining room is now TPIR's until they give it away. They're not making money on it, and Broyhill isn't looking for it to come back. Cars are now paid for by the show as they're won.
-Jason