In my opinion, are only those coins mentioned in the Bible. That leaves very few because there are not many mentioned in the Bible. I suppose it is not a huge stretch to include coins from Judaea as Biblical, since they are a major player in Biblical history. There are no set dates for "Biblical coins"- I can't tell you they started being minted at this time and stopped being minted at this time like I can other coins. I certainly won't include Byzantine coins here, they are absolutely not part of the Bible. So, as you can see, the term "Biblical" is a loose term numismatically speaking. With that being said, Judaea had an extensive mintage and should provide the basis for a collection. There was also a "Judaea Capta" series minted when Rome captured the rebellious Judaea.