No, I have never won anything from a receipt survey.
No, I don't feel you would be wasting your time entering them...most times the receipt survey has to be entered in a certain amount of time. SO therefore, your odds may be better than you think!
Of course, I am one to talk, I have a whole table full of receipts that I have to enter(someday). Now, whether I will ever get around to entering them-- well, your guess is as good as mine.
The only receipts that I enter consistently are the kroger receipts because I can speed thru the survey. I have never won anything from it.
Maybe this is a sign to me to enter them.....Afterall, like you say $1000 (wow) nothing to lose!!!
GOOD LUCK