1x:2x = 60:139 ???

It's more like 1x:2x = 3:3.5 or 3:4 in OEM prices and US retail prices and the cheapest 1x costs 1,800 SKW and the cheapest 2x costs 2,200 SKW in South Korea. (And many of those 1x disks can be written at 2x depending on the drives and firmware.)

4x media from Taiyo Yuden, Mitsubishi, Ritek, TDK, Pioneer, etc. cost about 50% more than 1x media from the same maker.

I mean prices for 2x and 4x media can fall anytime these days. I don't expect a Princo 4x DVD-R to cost more than 1 Euro in OEM quantity. But much less than 100 Euro price difference may not matter that much which anyone can earn by working a few more hours (part-time jobs in Seoul usually give 1,500 to 3,000 SKW per hour).