hi , anybody know their difference ? price level ? what is the R stands for ? please advise . thanks .

No difference at all, they are identical in every way.

The R simply means it was sold as a replacement item and not supplied with a beogram at the time of sale.

Weren't the R models sold in a simpler packaging (a styrofoam box instead of the transparent plastic tubes) and without calibration data, just like the regular MMCs were sold the last couple of years? However, I doubt there was any other differences than the packaging :)

That's correct Henrik.

As you rightly say though there were no differences at all other than the packaging and the designation of the letter R.