Residency has benefits. Getting a bank account, phoneline, utilities and ADSL for example. Also you never know that you may accidently go over your tourist visa which would incur extra costs and persona non gratia for a period aswell.
Add the costs of travelling, visa (who knows what the cost will be in 5 years, it was free when I first came here), what you would spend for food and shopping when you wouldnt need to, then there is not much different in cost.
Also you will need a residence to buy a car too.