Family Value Plan Question (Adding More Devices)

Hello,
I have been enrolled in the Family Value Plan with one device for several years. It's great, no issues.
My question is, if I wanted to add two additional phones to this plan, will the price go up? Or, will it be the same price but all three devices will share the account balance?
I rarely use my phone, so I have accumulated a lot of minutes and data. It would be great if I could share this with three devices instead of one without paying more. All three phones would rarely be used. Mainly for emergency purposes. So the balance would be sufficient for all three.
Also, out of curiosity, if the balance is shared among all devices, is there any sort of limit as to the number of devices? So, for example, what if I went all out and added like 20 or 30 phones, would the balance still be shared?
Thank you.
I have been enrolled in the Family Value Plan with one device for several years. It's great, no issues.
My question is, if I wanted to add two additional phones to this plan, will the price go up? Or, will it be the same price but all three devices will share the account balance?
I rarely use my phone, so I have accumulated a lot of minutes and data. It would be great if I could share this with three devices instead of one without paying more. All three phones would rarely be used. Mainly for emergency purposes. So the balance would be sufficient for all three.
Also, out of curiosity, if the balance is shared among all devices, is there any sort of limit as to the number of devices? So, for example, what if I went all out and added like 20 or 30 phones, would the balance still be shared?
Thank you.