It's not necessarily that Andy doesn't have $2,500. He needs someone to cosign the bail. It's like a loan, and unlike bullshit reality TV shows, bounty hunters don't typically go after the criminal. They go after the person that cosign the bail because they will have to have a job, property, and long term residence.
So say you cosigned andy's bail, he skips bond, the bail bondsman comes after you and your property for the total amount $250,000.
They don't need to track down and coax Andy out of a tree, high on crack. And clearly, Andy doesn't know anyone that could qualify to cosign his bail, that is stupid enough to take on that risk.
Andy could have a million dollars cash to his name, I doubt he could find a cosigner to get out of jail.