That's great feedback king2256. Currently we do provide free SIM cards when a troubleshooting scenario points to a defective SIM as a potential culprit, but otherwise they have a cost associated. We occasionally run promotions where the charges for a SIM are waived (like with a new line, for instance), but not always. Was there a specific scenario you were thinking of? I'm happy to forward your suggestion!
As stated, if you have a troubleshooting issue that points to a defective SIM, I can see T-Mobile replacing it for free. But, if you just lost it, or damaged it yourself, I can see there being a charge for that. There might be other instances like taking a nano SIM and having to use the 3-size card adapter to make it fit in a phone that uses a micro SIM....if that adapter frame broke, maybe the SIM or the adapter could be replaced once.