What type of phone do you see now and what are you looking for. I use an LG G6 and its by far the worst phone I have ever used. The fact T-Mobile is still trying to sell it for $550 plus tax is unbelievable.the only phones I would possibly consider getting with T-Mobile would be the note 8 and maybe S9+. I am actually considering the oneplus6. Its not officially carried by T-Mobile but its unlocked and will work on the T-Mobile network
If you're looking to Upgrade your device , we have a few different methods you can use. If you already know which one you want, feel free to take a look at the link I posted and it'll give you some steps on how to buy it.