2 Less attack, its already more than half the price. Your 133att 6.5b, this guys 131att 3b. 3.5b difference for 2 att https://royals.ms/forum/threads/s-131-15-st.201503/
You're right. Its nothing wrong to undercut prices, definitely on the cheaper side with that one. But I highly believe 133 around 6b is reasonable, basically 1b per attack.