Those brands are not that great, a good chocolate bar should run you about 4 dollars and up. Theo is good, Green and Blacks, and other artisan brands.
I bought two 90g Green and Blacks 70% cocoa bar for 2.45 euros. The Lindt 70% cocoa bar costs 0.45c more and is only 10g more in weight, at 100g. Do you think the Lindt having a higher price is from local perceptions of it being a higher quality brand than Green and Blacks, rather than it actually being so? Interestingly, the Green and Blacks 85% cocoa bar was the only bar in the Green and Blacks row that was sold out. I will keep a look out on it.