Advice On Buying An iPhone

[Tenarrows]

I've had two iPhone's both purchased used from Best Buy. An iPhone 6 and an iPhone 10. I really had no issues with either. The iPhone's were in excellent physical condition and I had no issues using them. Except I noticed my iPhone 10's maximum battery charging level was already around 80%.
Its now at 66%.

I need another iPhone to replace my iPhone 10. I'm thinking of getting an iPhone 13 from either Best Buy or Amazon. (Amazon prices are lower).
But I'm concerned about getting a used iPhone with a depleted battery.

I cannot afford a new iPhone out of pocket so it would either have to be used iPhone or a new iPhone with a cellular plan.

Any advice on the best reliable retailers for used iPhone's or cellular plans that include an iPhone in the deal? Or if upgrading from a 10 to a 13 makes sense?

Thxs!

 

[MightyGem]

If you are happy with your 10(as I am with my 8), how about a new battery?

 

[Tenarrows]

I forgot to mention I'm having issues with the iPhone. I randomly lose cellular service. Its now a daily occurrence. Ive determined its not the cellular provider or location. So I figured its time to upgrade.

Two other reasons- I need my phone for my job so I need to be up to date, my apps must work for signing into work and I need to know iCloud service continues to work between my iPhone and iMac.

Finally I'd like a larger screen size. That's a luxury but if I'm having other issues with the iPhone might as well upgrade.