Sergio,
It really depends on where in Spain he visited and what frame of mind he went with. Large cities like Madrid and Barcelona are outrageously and unrealistically expensive nowadays because from a tourism stand-point they feel like they can and should be competitive to other major European capitals, not keeping in mind that in these other European capitals, the people earn considerably more, so this thought process ultimately affects the people that live and work there.
Also Spain is notorious for a very wide sliding scale when it comes to pricing on travel: (IE: I have stayed at a nice four star hotel in Costa del Sol (comparable to a Marriott resort hotel on a normal, nice beach by US standards), South of Spain, that in August charges 280 euros per night, and off season the rates can go for 39 euros per night for the same room. Airfares and train fares are similar, especially in markets where there is a monopoly IE: Iberia being the only major airline covering that route directly,etc)
Tourism-wise it is true that because Spain has suffered a lot in this sector and it is one of the primary industries and I would not be surprised to hear that he was able to snag some really good tourism-related deals (IE: hotel, transportation, etc) and thus came back thinking that his native country isnt so much higher in price than one where he has relocated to.
Anyway, enough about Spain and on to Argentina, I'm a firm believer in that you only regret what you do not do, so I will most likely be making the move down, however, I do appreciate hearing different people's opinions and perspectives and it is all food for thought, both the positives and the negatives.
I will also say this in relation to the salaries: Depending on what you are looking for, I find that it is really relative. In the US, we may make a lot more for example, but it would be futile to argue that there are some expenses that you will not incur living abroad that are fairly normal day to day things in the states, and thus the need to command such a high salary is not as important. In Argentina, basic health coverage (ok, now Im expecting a backlash on how the basic isnt good enough and everybody has private insurance) and a good education/university are free, these are 2 of the major things here in the States we pay and are encouraged to save up for. Also gym memberships and vehicles. If I can walk to 95% of the places I need to go to, I save myself from having to pay to go do excercise (this is in my case in particular) and it also saves me the price of the car, gas prices, and in large cities like Chicago, a parking garage spot downtown at around $250-$300/month.