Among many unknowns we have...
1) Will there be another referendum??
2) Who will pull the trigger and activate article 50 - officially indicating Britain wants to leave the EU.
3) How soon will this be done? Three months? Two years? Some Brexit proponents now claim they have up to four years!!
4) Will there be pre negotiations before invoking article 50?
5) Will the EU try to make an example of Britain or is it likely to be a friendly divorce?
6) What model will Britain get? Common market? free movement?
7) Will Britain join the WTO?? It was a member of WTO through EU.
8) When will they get the next Prime Minister.
9) Who will be the next Prime Minister??
10) Will Scotland block BREXIT?
11) Will Scotland leave the UK?
Etc.
Not a nice environment to have you money tied up!
Never count on making a good sale. Have the purchase price be so attractive that even a mediocre sale gives good returns.