That guy is talking about east european border nations - some of them are still 3rd world status because communism wasnt that cool in the end.
Don't know where you're getting your knowledge about world economy, but there are no nations of a 3rd world status in the European Union, not even close.
In third world countries, or postcolonial countries, citizens usually have to survive on less than $100 a month. Wages in the EU start with 400 a month, which as you can see is completely incomparable.
I don't know European countries where the salary is 400 euros. The minimum wage in Germany, 1080 euros. In poor countries, and lower prices. Should not be considered wages, and purchasing power. In Germany, you will not live on 100 euros a month.
AFAIK, Bulgaria and Romania are in the 400 range, with Lithuania and Hungary being just 100 above that. I'm aware that purchasing power might be different, but they are all in the Union with open borders. You can jump in a car, do some shopping in a neighboring country and be back in less than 2 hours. PP line gets blurred when the borders open and on one side you have people earning twice more than you do.
I wasn't talking about the minimum but the average.