Alza has BRIX in stock. However, it is not possible to walk to the shop and get one: you have to pre-order and provide an email as well as a mobile number to be notified when they are available. You can however opt to pay in cash upon delivery. When we were there this week around 7pm it was very busy: I’m not sure how long you have to wait in line for your order to arrive but I would expect it is more than a few minutes
Paying in cash is better but paying with a credit card is also ok. What we try to avoid is not that someone knows who bought a BRIX. We just want to make sure the pre-order mail & mobile does not reveal the identity of the buyer so that there is no trivial way to when a given BRIX will be picked up from Alza. Without this knowledge, the chances that the hardware is tampered with are reduced.
I created a protonmail account for the purpose of pre-ordering. The next step is to get a disposable SIM card from a shop.