I haven't sold that much on the forums but I have some. I have received some offers I rejected, and I read in GBU regularly.
Here are some general things a buyer (or seller) might say that start to make me nervous:
1) Time constraint - Need it by a certain time.
2) You will have difficulty in reaching me - Going out of town, email down, I work 3 shift, ...
3) Something bad happened so I don't quite have all the money
4) I'm doing xxx for charity but don't have a knife..
5) Keep information a secret - don't tell people something, price, what I said, etc.
I'm sure I can think of some others.
Here are some general things a buyer (or seller) might say that start to make me nervous:
1) Time constraint - Need it by a certain time.
2) You will have difficulty in reaching me - Going out of town, email down, I work 3 shift, ...
3) Something bad happened so I don't quite have all the money
4) I'm doing xxx for charity but don't have a knife..
5) Keep information a secret - don't tell people something, price, what I said, etc.
I'm sure I can think of some others.