if i sent international + the cost of sending in usd (i have no idea how much it costs to send a letter from the us, only sent postcards), will you honour it?

if i sent international + the cost of sending in usd (i have no idea how much it costs to send a letter from the us, only sent postcards), will you honour it? (i have a fuckton of us coins at my place that i have no use and it's not worth to exchange them)