The $60 10gb plan is available to anyone but its a Bring Your Own Device plan (BYOP).
You can switch to it but you will not be able to get a subsidy on a phone and if you are currently in a contract you will need to pay off the balance of your current tab in order to switch.
@KAPABLE-K is correct, the $60 version of the plan is BYOP and not eligible for an agreement. You can get a new phone with it, but the phone will be at full price.
We do have the same plan available in the Large tier though. It would cost $85 and you can get a phone on agreement with Large pricing on the phone!
Hope this helps