3% sounds about right.
TTC reported recently that the overall cost of fare collection is currently 7% of total passenger revenue, and that it would remain at 7% after Presto is implemented - and the only increase in cost would be temporary while they are in the midst of operating both systems simultaneously. Given that TTC will still have to have the ability to collect cash, plus maintain the various collection devices at stations, on vehicles, and at streetcar stops, that costing 4% on top of the stuff they'll no longer have to do (print passes, tickets, ship tokens and passes around the city, etc.)
That makes no sense. Firstly, TTC is going with PRESTO - they've made that clear. Secondly, TTC has said it won't cost any more to go with PRESTO when fully implemented. Is this source just theorizing?