I would not take any amount of money for the 100% loss of the use of either arm

In New Hampshire it is a percentage of your total income. Someone who makes 30.000/year has an arm worth much less than someone who makes 100.000/year.

A person losing their arm or the 100% use of it while working in the state of NH will receive 210 weeks pay at the rate of 60% of what they were taking home per week.
http://gencourt.state.nh.us/rsa/html/XXIII/281-A/281-A-32.htm

So if you take home 1000.00 per week and go out on WC you will get 600/week in WC pay.
600/week x 210 weeks = 126,000 that's is how much this persons arm is worth if lost or 100% unusable.

as you can see you arm might be worth more or less than that example.

Plainly unfair to have one persons arm worth more than another.

In a work related accident in 2000 I lost the usage of 7% of my hand permanently. My hand is worth 189 weeks at 100% loss of usage (I got 7% of 189 weeks) of pay at 60% of my take home. I was taking home 350/week then. As you can see my entitled compensation was minimal.

I doubt that I would take any amount for either arm, as they are both prime tattoo real estate.

However, There's always a possibility that if I took around 3 million bucks, I could get a pretty legit prosthesis.

I've known people who lost one arm, and one person who lost both.

In the jurisdiction I was in at the time there was no private health insurance, rather, there was one government controlled insurance scheme, and when an accident like that happened, you had to file a claim showing how much it was going to cost your ability to continue to make a living without that arm, which meant that the payment could vary a lot depending on if you were doing things like logging that required both arms.

What I saw was that those who'd lost their non-dominant arm (left arm if right-handed) seemed to settle down about it if it was in the $150K range plus cost of retraining for another field.

If it was their dominant arm, they settled at around $300,000 plus cost of retraining.

When it was both arms, however, no amount could make the guy happy, and he didn't stop filing claims until the insurance scheme set him up in a reasonable apartment with a full-time live-in Filipino caregiver, and enough budget to live a moderate middle-class existence with no expectations ever to retrain and find something else to do, and all he did was drink, and do drugs, and eventually drowned himself, although it was written up as an accident... which means, maybe you can put a price on one arm, but there is *no* price that can cover loss of both.

While I'm sure you were looking for a specific amount of money, I'm going to argue that most people value their arms very little--until they lose them.
My example actually applies more to legs, but I think the principle is the same.
Many people have diabetes. They know that one of the complications from diabetes can be decreased circulation leading to trouble, often resulting in amputation, of the foot (or feet). The easiest way to prevent this is through regular medical care and amintaining their blood sugar levels, but many don't. So the cost of a foot is basically the willpower to maintain their blood sugar levels and the cost of thsoe doctor visits.
I'm not casting aspirsions, I have done it too. In 2005, I was diagnosed with MS. I lost a lot of feeling in foot and lived with it rather than spending thousands of dolalrs trying to find a cure or some sort of help. I stumbled upon a solution this year and the cost of keeping my foot health is apparently the cost of living gluten-free. Now, I'm willing to pay that price, but a few years ago, I might not have been.
For an arm or a hand, consider the problem of repetitive stress. Thousands of people every year end up with repetitive stress injuries, diminishing the use of their arms and hands, but forgo the treatments or the surgery because of the expense.
So, my honest answer would be that we value our limbs very little--until we are without them.