Why do you assume the consumer will always be short changed? Just use mathematical rounding which is fair. It's hard for merchants to price items so that the to

Why do you assume the consumer will always be short changed? Just use mathematical rounding which is fair. It's hard for merchants to price items so that the total ends up rounding upwards if you buy multiple items. People already subcontiously read 99c as $1 and will apply that thought even more if they know rounding will happen so it's not exactly like you are being cheated. For larger purchases even more so, would you consider $99, $99.99 or $100 different prices? No, the difference is irrelevant since the competitor across the street sells the same item for $89. Even if you were being short changed at every purchase, assume 10c being the smallest coin available, you loose worst case 9c per transaction, assume you make 2 transactions per day. That's total $5.4 lost per month, I can live with that. Especially since it's a worse case scenario, realistically it's +/-0 and even if merchants have a special secret method for winning they can probably only win 5c on average making the loss half of my worst case scenario.