Does anyone know under what conditions JLC PCB offers free shipping? A few months ago, I bought 10 boards just under 100x100mm for a "special offer" price of $2 + $18 for ENIG and got free shipping (~18 USD to the continental US).
Today, I tried to place an order and found that their site was down for most of the day, throwing 500 & 502 HTTP errors frequently. However, I was able to get far enough in the ordering process (which would have been around 5AM in China on Saturday at the time) to see that shipping was free... but I wasn't able to actually place the order. Fast-forward to later (around noon in China on Saturday), and on re-visiting the order page, boom, no free shipping available anymore.
Is this perhaps something that goes away on weekends...? Should I consider waiting until Monday to place an order...? Is there any info on this anywhere...?
Btw, that order contained two boards, one 2.75"x3.75", the other 1.5x2.5". For some reason, the first (larger) board was $2, but the second was $5-ish. Why is this??? I don't understand JLC PCB's mystery pricing model.