Propane is sold by the gallon, but the tanks are measured by weight - pounds. How many gallons fit into a 100lb tank?
Or, if propane now costs RD$93.80 per gallon, how much does it cost to fill a 100lb tank?
Remember that a lot of stations for gas and gasoline rip off the clients by not actually giving the client the gallon they paid for by having fraudulent filling gauges. My feeling is that this is the norm rather than the exception. Therefore, do not be surprised if it costs more than you correctly expected it should cost.
The facility to commit fraud in the sale of LPG is huge:
a) a nearly totally illiterate demographic
b) people unwilling to go themselves
c) easy to manipulate
Which is why they are now installing scales in most places...however, scales can be fixed.
So, you know that you should get 23.5 of 23.6 gallons of LPG and the tank should weigh 100 pounds more than it did when you started.
Or find an "honest" camioneta driver....good luck with that...