John...Assessed value has a limited correaltion to market value. An assessment is only a tax basis and is an average of tens of properties. An offer should be based on recent pendings and solds, what you feel it's worth, what you can afford, what work needs to be done, seller's motivation, location,features, ammenities and others for sale. Value is different for every property and perceived differently by every buyer.
Also, if you're getting a mortgage, you'll have an appraisal done by an independent party to insure what you're buying is worth the sales price. Plus, use the resources of an experienced expert in Glen Allen.

Do not go by the assessed value as the final-be-all point of reference for an offering price. Speak with an experienced, knowledgeable and reputable agent who's very familiar with Glen Allen to get guidance on market values.

If you'd like recommendations on good buyer's agents in Glen Allen, let me know and I can provide those to you.