No matter what the job is, finding cats, to avenging a murdered child, all it takes for Yato to grant those is just a measly 5¥. I suspect that this practice dated back from during the time when Yato was actively known as God of disaster. Since there is inflation, while 5 ¥ now worth almost nothing, it must have worth a lot more in the past. If this is the reason? Then how much far in the past was the year that Yato was actively known as the God of Disaster if we are to use real world's currency value.
If this was not the case, do we know why the fee is just 5 ¥ while other Gods have it more, which can be seen from their lavish and abundant number of shrines.