Flipping (renovating) our French house to buy a boat

The Time has come, we are in a Race to Renovate and flip our French house so we can buy a sailboat. Many of you have followed us from the beginning and know this channel was created to follow our search for a boat to take us around the world.
We have a deadline and a chance to work with a shipyard, but we are in two minds about whether to work with them and finance a large part of a sailboat or go old school and purchase a second-hand boat with no debt and just set off.