I want to use the pcb assembly for the first time and have my
design ready. But after uploading the gerber, bom and pick and place the
prices do not match!
The section where I have to confirm the parts seems ok, but the final prices added to the card do not match.
Some prices are exactly twice the amount, some are correct and some are slightly higher.
I found 1 part witch is actually cheaper.
Some Examples ( 10 pcs order quantity):
| ID | Name | Designator | Footprint | Quantity | Manufacturer Part | Manufacturer | Supplier | Supplier Part | LCSC Assembly | Unit Price | Total | Order | Difference |
| 3 | ADUM1201ARZ-RL7 | U1 | SOIC-8_150MIL | 1 | ADUM1201ARZ-RL7 | ADI | LCSC | C9669 | Yes | 0,95 | 9,46 | 10,40 | -0,95 |
| 14 | 12MHz | X2 | OSC-SMD_4P-L3.2-W2.5-BL | 1 | X322512MSB4SI | YXC | LCSC | C9002 | Yes | 0,11 | 1,10 | 2,20 | -1,10 |
| 31 | INA199A3DCKR | U7 | SC-70-6(SOT-363) | 1 | INA199A3DCKR | Texas Instruments | LCSC | C132098 | Yes | 0,36 | 3,57 | 7,13 | -3,57 |
| 34 | 0.002 | R15 | 2512 | 1 | LR2512-22R002F4 | RALEC | LCSC | C108929 | 0,08 | 0,76 | 1,51 | -0,76 | |
| 35 | 4.7uH | L3,L4 | SMD-L-7.1X6.6 | 2 | MWSA0603-4R7MT | Sunlord | LCSC | C132139 | 0,18 | 3,57 | 2,66 | 0,91 | |
| -5,4608 |
For completeness the answer from support:
Thanks for your e-mail , so sorry for that for some component , it
will have supplement for the component , so it's not same as cost what
you need .
And please kindly to revised the BOM file format as below:
Brand new interactions and interfaces. 
Easy to use and quick to get started. 
It's normal if you use components where the reels have to be hand-loaded onto the machine, there will be a surcharge.
Many parts are marked "Extended Part" on the parts list, but it doesn't say if the listed price includes any surcharge or not.
https://jlcpcb.com/client/index.html#/parts