Good question. I have found that many third party approvals need 2 property valuations; often a BPO (which may or may not be worth much) and a second evaluation/opinion. In my experience, it is prudent for the agent to run a set of comps to send with the offer package to indicate where the market is at that moment. Once credible valuations are on hand, the negotiator can move the process along -- accept, or counter. Oftentimes with a good package - things can happen in 30 days; otherwise expect 45-60 days+. You need good agents who will stay on top of the process.