Start by reading this......
Do NOT part with any cash before you ( and your experienced friends ) check out the boat in the flesh .
Perhaps the only exception to this is an agreed small deposit to sea trial a boat ( and this would normally come off the total price if you actually bought said boat ).
You will hear from some experienced folk on here that they have bought unseen good boats , but they almost certainly know what they are doing , and have not just been lucky .
If you really like the look of a boat , even if it's up in Scotland , perhaps ask on here and someone will tell you whether it's dodgy or not.
Good Luck and Happy Boating.