While exaggerated, Lawrence makes a very valid point. A lot depends on what it takes to make the shots. Are they bringing product to you or are you going to them? Do you have autonomous creative control or are you working with someone? How much tweaking do you expect to have to do in post? Lots of factors.
While asking the customer to name their price may lead down a tricky road (if their number is purposefully understated you can go higher, but if it's not you could be out of a gig), so a lot will depend on your relationship with the client beforehand. My first batch of product shots was a barter job where I traded about 20 hours of work for a complete set of graphics for an as yet to be branded photography business to be delivered in Q1 2014. I've done work with this guy before, including recording a bunch of music for a customer event he was doing that I made out on fairly well, but this was for him, and I don't like taking money from friends when we can trade favors. That said, my work got me an offer to do studio work I'm not ready for, on location, so there's promise for a future of that yet-to-be-branded business.
My recommendation would be to call around to existing local studios and ask for quotes based on what you're being asked for (assuming there's a potential gig) and make your quote based on that. I'm a firm believer in breaking even in order to prove yourself, and making your money off repeat customers. If they like your work and come back then profit off the subsequent jobs.