$125 is way high. If you're willing to pay shipping I'll give you one of my old 3Gs jailbroken and unlocked for free. Bear in mind you'll need to buy a data plan from your current carrier or else you won't be able to use any cellular data, the phone will act like an iPod touch where you can only get data over WiFi. The 3G and 3GS use standard SIM cards, the 4 and 4S use microSIM, but even then, the card internals are the same. You can literally take an X-acto knife and cut a SIM card to microSIM size and it works just fine.