Yeah, that's fairly normal for Verizon's online ordering system.
As for Best Buy, you have a couple of options. The original Best Buy method was just using the upgrade on the unlimited line, destroying the SIM that shipped with the phone, and using the already active SIM that is linked to the account. You could definitely go this route.
The other way to use Best Buy is to transfer the upgrade to the tiered line through their system. Transferring the upgrade through Verizon's system doesn't stick. In other words, once you leave Verizon, your upgrade returns to its original line. In the past, Best Buy would allow you transfer the upgrade in its system. However, that has become very hit or miss. Cruzmike89 was able to do it a day or so ago, by doing the following:
1.) Go to
https://www-ssl.bestbuy.com/site/ol...wNw-PGvbkfWcFLLeNF1serv0gg#connect-to-account
2.) Put in the phone number that has the upgrade on it
3.) Select a phone and then check eligibility again
4.) The next page will say that you can upgrade but don't do that. On the same page on the mid right it will say something about trying a different number. Click on that.
5.) It will take you to a new page and that's where you put the number that has no upgrade available.
6.) The next page will say you can't upgrade but you can transfer your upgrade. In the scroll area pick your number with the upgrade and continue to transfer.
7.) Finish your checkout.