How much would it cost me to switch from cricket to T-Mobile. I want the cheapest monthly phone bill for the IPhone 8 plus phone?

I want unlimited, talk, text, and data, with a hotspot. But I need two lines. I just wanna know the price before the cost of the other phone. Just wanna see if anyone knows a round total of what it might be.

Their website will tell you exactly the cost.

You really need to understand what you are currently CONTRACTED to! As you are asking about the price of the other phone, then you are probably paying for the phone as a part of your current contract, which probably has 12 months or more left to run. If that's the type of contract you have then you'll probably save little to nothing by changing contracts because you are still going to owe for the current phone as well as having to pay an exit fee to get out of your contract!