I placed an order with them. The price really goes up if you change anything, i.e. soldermask color or copper thickness. I needed 2oz. copper, and the price went up from $2 to $20 for 10 boards. It's funny how 10 boards cost the same as 5 boards.
I just hope that a 2.5mm trace width with 2oz. copper and then solder applied the length of the trace on BOTH sides of the PCB along that trace can handle 30A (will probably never see 30A, but the relay I have is capable of that for switching).
My design was 100mm x 100mm and 3 different designs (8 total boards on the 100x100 panel). There was no option to select different designs, so I hope they don't come back and say they need more money from me. If that is the case, I may cancel order and order from elsewhere, as the cost would then be the same as another manufacturer, and I could get a different color solder mask (I really hate green, but for prototype is okay).
The board I designed was for my Vehicle Alarm. It is used to cut of the fuel with a manual switch, but the remote start would still work (remote start on remote will override the manual switch). I tried to buy this circuit from the Alarm Installers here in my city, and it seems that nobody makes this. Basically, if you have remote start, you cannot have any manual switch (hidden) to cut-off the fuel pump, as the vehicle won't start unless the switch is manually turned on. My circuit solves that, I hope.
I'll let you know how the order goes. I almost didn't order from JLCPCB as there was a post some time back of that manufacturer spamming this forum.
Total Price $49.70 with Stencil and 10 panelized boards shipped to USA with DHL.
Order placed at 5:30am PST on 11/6/2017.