kindly post a signed message to prove you have 2btc
Can't, since I was sending from an online exchange account which has no provision to sign an address. But since a trusted forum escrower will confirm funds are in escrow before any fiat is sent, it shouldn't really matter, no?
For a small amount such as 2
BTC, there is really no need to prove control of funds prior to escrow being setup because it is not uncommon for people to have such a large amount of money.
If it were a larger amount (say for example 20 or 50 BTC) then it would probably be a good idea to prove control over an address that has as much as you claim in order to prevent people from thinking you are going to waist their time.
It probably would be better for you to keep the BTC in an address that you control though, it will prevent you from loosing money in the event that the exchange (or your exchange account) gets hacked