It is nothing to buy, you don't own it, you have to hand it back after the two years are up. They hope that by then you will want to have the latest version with all the bells and whistles. There are already half a dozen newer Nokia models out which do everything except make the tea.
I got this one because DD2 and SiL (and DGS1) all have a slightly newer model and I liked it when I had a shot with it. The 520 did enough for me, but the family are into having everything faster and glossier etc, but I am not. It is very good for texting and emailing, and it has things like a notebook where you can make a shopping list and so on.
I don't use the internet part very much, except for getting bus times and the weather. The screen is not all that big. My tariff is with Talkmobile, and gets me 100 minutes of phone calls, 5000 texts (!! I could be texting all day) and 250 megabytes of internet. I have nothing to compare it with, but it works OK for me.