Each building has its own refund cost, if you place 5 roads one after the other and refund them starting from 1st road you placed, you lose money.
I mean you don't lose money if you sell all of them, but my road cost 1024, but selling one of them gives back 32.
It should refund based on the road type only.
Or even better, if you can just buy a road and it stays in your inventory as a puzzle piece.