Common wavelength of BIDI optical module

The advantages of BIDI module: BIDI optical module is relatively expensive in unit price, but save fiber resources, only need one fiber. It is a better choice for users with insufficient fiber resources or those looking to upgrade fiber optic network without laying new cables.
The advantages of dual fiber module: The both ends module don't need to be used in pairs, any 2 can be connected. It's cheaper than the BiDi SFP optical module. But needs two fibers, can choose the dual-fiber module if the optical fiber resources are sufficient.

Cost Analysis: Which is More Economical?
How single-fiber modules to save fiber resources? Let's do a simple cost calculation:
For example: Dual-fiber module is $6/pcs, BiDi SFP for sale is $10/pcs, patch cord is $0.15/pcs.

Which do you think is more economical? I believe you have the answer in mind!

BiDi optical module may be a little expensive than the common optical module, but it can save you the cost of optical cable from the whole network program. ETU-Link offers various rate compatible BiDi modules and stand