I have a new local dealer that's weighs the 90% Kennedys instead of by the $1 FV buy. But then wants $3 over spot. So I didn't know if thats a good/fair price? I'm used to the typical per $1 FV when buying 90% coins.
If you can remember .7234, you can use your phone to quickly calculate it. Just take spot (x) + Premium (Y) Multiply by 0.7234. Here's an example: X + Y * 0.7234= $18.89 + $3.00 * 0.7234 = 15.84 I rounded up to the second decimal.
Kennedys hardly circulated, so in general they'll be close to their full original weight, and it doesn't matter whether you weigh them or count them. $3 per troy ounce over FV isn't bad; neither is $3 per $1 FV over spot, as premiums are always high when silver falls as far and fast as it has recently. If the same dealer wants to weigh slick Barbers, Mercs, and SLQs instead of counting them, buy all you can. If he wants to count those, but weigh Kennedys and 1964 quarters and modern silver proofs, shop elsewhere.