I know PA does not have any sales taxes on Precious metals as I've purchased locally from there before, and I just looked up from a Local dealer in Boston, that Mass has a sales tax on Bullion sales under $1000, so either way you are in the green. You do have to pay capital gains taxes, however if you are buying $50,000 worth of gold, and selling it for $50,000 that shouldn't be an issue, since there isn't any capital gain. If theres a small variance, you should also be fine, however if you make $50,000 on a huge gold swing, you will have to pay a tax on the profit.
The reason different states vary as to whether or not they have sales tax, is based on what increments if any they agree that precious metals are an investment. While in PA, they don't tax Percious metals at all, Mass made the decision that its an investment purchase if you buy more than $1000 worth, so there is no sales tax on purchases/sales over $1000 in Mass. The Capital gains tax is similar to any investment such as stocks. You are required to pay I believe its a 20% tax on capital gains. So as I said before, if you buy $50,000 worth of gold, and sell it for $50,000. You will be subject to no taxes. If you buy $50,000 worth of gold and sell it for $60,000 you are required to pay that 20% capital gains tax on the $10,000 you made. If you buy $50,000 and it drops, technically, you could get a tax writeoff.
Source for Mass Sales Tax:
http://www.bostonbullion.com/faq.htm#9"There are NO sales taxes on out of state orders or Massachusetts bullion purchases larger than $1,000."
Source for PA Sales Tax:
http://www.jmbullion.com/guide/buying-online-vs-locally/" For example, JM Bullion is located in Pennsylvania, which doesn’t have sales tax on precious metals sales, thus we never charge any of our customers sales tax."
Source confirming both again:
http://preciousmetals.wikia.com/wiki/Bullion_Sales_TaxTechnically, you could do everything off the books anyway, since like I said, Precious metal sales are done in cash, however I'm explaining the legal way to do it, which I'd probably reccomend, since you shouldn't have to pay any taxes anyway.
