What do you call this? (the More You Buy, The More You Save)
For example, if you buy 1 chicken, you pay $8, but if you buy 2 chickens, you pay $15 (instead of $16)
If you pay monthly for a gym membership, you pay $50 but if you pay for a full 12 months in advance , you pay $420 total, thus saving you $120.
I just want to know if there is a word for this saving concept.