They could also make job more attractive. I certainly know people who have the skills and passion to be attracted to the idea of a postdoc, many would even accept the pay they're currently offering. What they won't accept is being worked to death on bullshit tasks irrelevant to their research and being treated as free labor by their superiors.

Treat postdocs with respect, give them plenty of autonomy and freedom to focus on their research, don't make them work long hours or use them as servants, and you'll no doubt find many people willing to take the job without raising the pay.