Guys, all the fuzz about the small change - ten or twenty centavos up or down the bill. You know who are the biggest scammers? The "bomberos" - not the firemen, but the gas station guys that fill your tank.
They don't give small change, even if it is worth pesos. Today I filled up my passola, at 206 pesos, so full that not one drop could get in. I gave him 210 - and - no change. Same as the time before, and before, and before.
The worst gas station is Texaco (at least here in Higuey), which ALWAYS shorthands you by many cents. I observed one time, for many minutes, where they fill all the motorcycles, and the 20-30-50 pesos always ended up somewhere between 30 and 70 cents less worth's of gas.
Counting that, when they do a final bill at the end of shift, having taken 50 cents on average from 200 motorcyclers, it equals to 100 pesos. Not a bad "tip" for these guys.
During my observation, I have pointed this out, the guy just laughed, and continued with his little practise.