I am selling an highly classified secret that I have held for over 50 years. Only an handful of people know this secret, I will not sell this to you if I think you are not trust worthy enough and or able to handle the information.
I would like to exchange your secret for my secret. As my one was held for over 60 years, it is worth more. Then you can get my secret for your one, once you send 0.05 BTC of difference to my address in the signature below.
I've decided for 24 hours promotion, I will accept only 0.04 BTC for the difference of secrets age.