The cast steel ones that come with most winches can be bought for fairly cheap. The aluminum ones are machined, so they're going to be worth more because of the machine time on them.
If you're looking at getting some made, it will depend on what kind of cable you run on the winch. Aircraft cable requires a roller fairlead or a cast steel hawse fairlead. You may be able to get away with using a material like Nylatron or another version that will stand up to the aircraft cable. I doubt that a titanium fairlead would be worth the money.
The first order of anything like this is going to be expensive. This is due to the setup, programming of CNC machinery, labour, material, etc. The more pieces you get done, the cheaper it will be per-piece. The more things you add like anodizing, engraving, or special features will also add to the overall cost.