AKA “Never never plant” tricolour. This looks like the original never never plant except it has an occasional white variegation.
I am willing to swap any other plant I have (mostly marantaceae, I’m still trying to get to grips with making a list and will update this post shortly) - also willing to swap money.
I was never under the impression that these were rare as they seemed to be everywhere a few years ago, but it does appear that they are now rare as hen’s teeth!
Please note - this is not the stromanthe tricolour / triostar with which the never never is sometimes apparently confused (There’s a visual comparison here: Which one is it? Stromanthe Triostar or Ctenanthe Tricolour? – lovethatleaf)