Think of the $20K as the true cost of the home. Most communities in the US do not use the bond structure. It's simply built in. The bond in a sense for some may make it easier to get into the home earlier than they would have been able to afford it.
Used home isn't always better value. We prefer new and don't intend to keep moving once we retire. We get attached to our home so once we decide on one, we'll make it our own and enjoy the rest of our retirement years in it.
Go for it
