I deal with a lot of Repo boats, Most will sell for about 50% of its retail price but you can not crank the engine or check compression no real knowledge about its real condition. A nice shiny boat does not make a good deal.
We haul and Repo over 100 boats every year, I see many owners get mad that their boat is being Repossessed. They try to take whatever they can and sometime even damage the boat - one guy added sugar to the fuel.
Anyways, there some good finds for sure but I will stay away from Repo boats unless you buy it from a dealer you can trust and will add some warranty to it.