User blog comment:The M.E.O.W. King/Ideas 13 : Boat Factory/@comment-7691217-20120621024123

Spike Research Facility: This is for the Spike Factory. It increases the price of Mortars by 5%.

TI: 500 Monkey Money: Spike Factories and their upgrades cost 10% less.

TII: 600 Monkey Money: Doubles spike deployment speed.

TIII: 1000 Monkey Money: Spikes will do extra damage to boss bloons (brown, M.O.A.B., B.F.B., Z.O.M.G.), and pop off two layers per spike!