Silver is lower right now, so this is a good time to buy. Holding on to what you have is the best choice at times like these when metal prices are lower. Engelhard and Johnson Matthey seem to have highest premiums over spot in most cases. There are several others that are decent as well, can’t recall at the moment what they are, though. Good Luck~
I rarely post in this section of the forum, but given the topic of discussion - investing in bullion bars, not only as precious metals but also as collectibles - I thought it might be a good idea just in case there are those who are unaware of what has happened in the past. I suggest any and all read what they find at this link - http://www.academia.edu/35912916/Jo...klin_and_their_Forgeries_of_Western_Gold_Bars - for it should serve as a warning and reminder of what can happen, and the care that must be taken if you are going to travel down this path.