Bullion in California follows the same rules as the coins. Under $1000 it is taxable, over $1000 it isn't.
Seriously, if you find the right coin dealer, even the (OUT OF STATE, TOO) little guy, won't get screwed. Now if you're a young Num.. a young coin collector who earns a whatever a week allowance, then you'd have to wait a while to get in on the tax break. And you'd have one heck of a coin as a YN. Spending $30 a week in a coin shop would take a little over 33 weeks to have $1000 on hand to spend and get the tax break. So you have to wait 8 months to get the break, if you want the coin and the break that bad, I could wait. Only the impatient little guy gets screwed. I was THAT GUY today. But I had to have the 4 SLQs in XF+. It was them now, or save up for that EF-40 1923-S ANACS CLEANED.... I went with the raw ones.
I just don't understand why the 'little guy' doesn't write to their representative to protest this tax. We don't all have the patience, nor does each coin dealer have the inventory to warrant a $1,000 sale. I collect Barber coins, and even if I want a Barber quarter, the 1896 S in good condition it only (only!) trends for $750. So I have to wait to buy something else to save the tax? Suppose the dealer doesn't get another coin that I want or need for my collection?
See if you can find another collector who wants something from that shop and the two of you get the transaction written up on one ticket so you can get the tax break.
In most states - generally businesses are not breaking any laws by charging sales tax on items classified as exempt but it is illegal to charge the customer tax on exempt items and then keep the money for themselves.
I don't understand why you're up in arms about the laws of another state. If you don't like it, don't buy coins here.