But with one post and zero trust, i don't think that some one will want to make deal like this with you..
Even in addition to what you posted I dont think I would probably want to patronize you, not because of anything but because I will be at the losing end in the sense that even though the premium youre offering is tempting but I wont be at an advantage because if I receive that $1250 by western union, as dollar is not my FIAT then I will lose more in the process of conversion because banks will give me at the official rate while at the same time I can exchange my $1000 bitcoin with exchangers at a better rate... But there is risk in every path...
I think it does not have to be a problem. For several years, I have not used Western Union, but from what I remember there was an opportunity to choose the amount that will be receiving. A local service gave the person that is sending money the amount that will have to pay to be correct with fees.