My ZX81 memory: I took the T to the Sinclair administrative office in Boston to buy a super-early one with cash money.

I had pre-flighted the transaction by phone, but it was still a strange thing for the office to do a retail transaction - I think my change came out of the postage money drawer. The machine was handed over in brown corrugate, without shiny shelf-ready packaging.

Many hours of programming and experimentation ensued.