New airbags from your local dealer will cost you $711.00 for the driver and $711.00 for the passenger. You will also need to replace the airbag module and the cost on that is $726.00 and the upper dash pad is $792.00. So the grand total is $2940.00 plus labor. However if you go with an OEM used airbag replacement system the driver/passenger and airbag computer, excluding the dash will be $375.00 (total). So new is $2940.00 used is $375.00. Huh, easy choice.
For discounted prices on OEM airbag replacement used parts visit http://www.airbagcenter.com
An estimate for an accident is very hard to provide unless you can see the vehicle. I would try going to a few body shops if possible, then having them provide an estimate, which many will do for free.
If your low on cash you can just get the interior damage fixed. I took my air bags out and sold them for $1,500 to a bodyshop years ago. Just hold on to the wheel if your gonna hit something............