Can we get a "Roam like home" type of add on instead of paying for only minutes, texts or data?

You can use "wallet" feature by putting money in it. You'll be able to use all features ( data, sms, calls, travel, international calls .... except voice mail - voicemail must be part of a plan ) at the pay per usage rate (higher).
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However there is a lot bugs in Wallet and this is not recommended at the moment, maybe in a few months