It will cost them the same amount to send you a R10 bill or a R500 bill. Rather make it uneconomical for them to bill you by just doing one gantry every week.
Unfortunately will not work.For this theory to work, you need a few things:
1. All road users must work together.2. Nobody should be registered.3. The cheapest toll gate must be used. (as the amount doubles if you are not registered)4. All other gantries must be avoided for as long as this continues.5. Do only 1 gantry per month. (4 per week will give you a bill of about R28, more than enough for them to print a bill and mail it off)
If you have registered e-Toll users and other people using other gantries, their fees will just make up for the short-fall of the few users who do this.