If Im a regular bitcoin user with a bitcoin wallet on my phone installed that can be use everyday to pay for my friends and to online stores that accepts bitcoin do I have to purchase another phone like this that can run a node? Is there any importance or advantages of using it? I think its not so practical using this kind of phone in my point of view, just a waste of money.
If you want to run a node, just run a node on your computer and store only a small amounts on your mobile wallet. Just like pooya87 said, running a node on your mobile phone is taking it a bit too far unless you find it ok for your phone to be frequently syncing, as it's going to drain your data limit and battery.
As for running a node, take it from the man himself, Andreas Antonopoulos:
https://www.youtube.com/watch?v=oX0Yrv-6jVs (P.S. There is no financial incentive to run a node if that's what you're thinking).