Could you elaborate on the estimated monthly cost of living comfortably in Spain for a single individual? It seems that around €1,200 to €1,500 per month is sufficient to cover basic expenses such as rent, groceries, and social security contributions. However, are there any specific costs or expenses that might vary depending on the individual's lifestyle or location within Spain? Additionally, how does the cost of living for a family compare to that of a single person, considering factors like family size and lifestyle preferences?