Unlocked Phones With No Sim Card Transfer

[Drury18]

I currently have an LG Muziq phone (if it matters, its a Virgin Mobile phone on a pre-paid plan as I am not a heavy cellphone user and have no intentions of having a monthly plan.) that does not have a SIM card in it as its a rather old and basic phone.

I am looking to buy some sort of used, unlocked Blackberry phone which if I am not mistaken you will need to have a SIM card for the carrier you are currently on in order to transfer the service over to them since the unlocked phone will not have a service provider.

For instances like this, is a transfer of service possible? Will I end up having to buy/obtain a sim card from my provider in order to get it to work? Am I missing something completely obvious?

[Hack&Lube]

You want to use the Virgin Mobile prepaid plan on a Blackberry? You'll have to call Virgin and see if they offer prepaid plans on SIM cards, that's all.

SIM cards not not expensive. I've seen then for like $10 on forums/websites.