how can I put this politely except each and every one of them laughed.
And that is ok. Of course, talking to your relatives via skype will give you a certain point of view, but remember, these are your relatives and they may not always be too negative when talking to you. Secondly, just because they don't do it, does not mean that the rest of Poland doesn't either. I have found it to be fairly common, to share things of own produce amongst the family. It is a kind of support and whether or not your family in Rybnik agrees, it is not that uncommon. I know of people in Lodz who come back home with a weeks worth of supply after visiting their parents or grandparents.
cost of utilities
they suggest allow 350PLN per month
Let's bring it up to 400. Now they two of them together have ca. 4100 zloty left for the month. With 4100 PLN, they each have a budget of 68 PLN per day which is "doable" but it also not necessarily a lot considering that roughly 20-25 PLN would be spend on travel to work and back (if using the car). Now we are looking at 43-48 PLN budget per day left. With 43-48 PLN left per day, he still hasn't eaten anything, bought any clothes, paid for health insurance (if not provided by the employer), paid for car insurance (if they will use a car) etc. etc. He also hasn't put any money aside for other unexpected expenses such as repairs in the apartment.
Lastly for now-we do dine out every day, in proper restaurants not fast food outlets.......you could as well if you so desired!
As a visitor to Rybnik you may very well do that but it hardly applies to someone living in Rybnik with an averge local salary.
you will be fine financially.
It seems to me that you have taken none of their expenses, which they will have, into consideration. My examples above may very well vary. He might use the train and buy a monthly commuter ticket but it will not vary from the above expenses too greatly. For someone who apparently visits Poland every year and appears to be spending a lot of time talking to relatives in Poland via skype, it is beyond me how you can suggest that they will be "fine" and can dine out every day on a 4100 zloty budget for both together. I am not saying that living on this budget is impossible, but it will be far from being "financially fine".