You will need a diagnosis first. Then a shop can quote you on the job. Use this link to find a good shop near you.
https://repairpal.com/repair-shops
Alex
RepairPal Certified shops can diagnose and repair your 2008 Chevrolet Cobalt. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
The a/c condensation drain tube has become clogged - vehicle will need to be hoisted to clear drain tube.
At the shop we charge $20.00 for this little job.
Price will vary Greatly