There are inevitable inner factors affecting PCB prices. Here is some information for reference but you can contact your manufacturer for details.

PCB offer: prototype and batch 

Prototype

Prototype has both common and expedited service.Common service delivery depends on the number of layers, one day for 1 layer board; three days for double-sided, multi-layer will require several to ten days. 

Quote:

Single-sided board costs 150 yuan + fabrication costs 0.04 yuan/square meter + film fee +0.05 yuan/square centimeter

Double-sided board costs 250 yuan + fabrication costs 0.05 yuan/square meter + film fee +0.05 yuan/square centimeter

Four layers board costs 600 yuan + fabrication costs 0.01 yuan/square meter + film fee +0.05 yuan/square centimeter.Depending on the difficulty of board, some factories will also add the test fee. Test fee is generally 0.002 yuan/point.

Expedited-service board has shorter delivery time.

One-day expedited service for 2 layers board costs 200-400rmb for each

Three-day expedited service for 4 layers board costs 600-1000rmb for each

Three-day expedited service for 6 layers board costs 800-1000rmb for each

Batch 

Batch is divided into small and large quantities.The unit price of small volume board is much higher than high volume. For example,450yuan/square meter is for double-sided 1.6MM board in large quantities. But for small batch, PCB processing manufacturers will not be willing even at higher price: more than 500 yuan/square meter.