Stick with vodafone for upgrade or sim free.

I am currently with vodafone bill pay with an old phone and am well due an upgrade. I have finally bit the bullet and have decided i might as well step up to a smartphone. I won't be using the internet that much, just for sports results and a few bets maybe. Calls and texting are my usual uses and this usually costs about 40euro a month.
What phone would be a good start for a novice user, a good basic reliable model is what I am after. Budget in region of 200euro and I would'nt like my monthly bill to exceed 40euro.
Should I stick with vodafone for upgrade or buy sim free and sign up with tesco for around 25euro a month. There is a lot of jargon and options out there and i am struggling/confused with the whole thing. All help is greatly appreciated. Thanks