Hi biz i have a rental property that i could pay off over the course of 21 months by building up 2700/month in savings and then throwing it against the mortgage without penalty when its up for renewal and increase my gross monthly income by 600 (currently i gross like 250 after the mortgage, property tax, condo fees, management fee (i dont want the hassle of interacting with a tenant fee), so gross 850). My buddy said that's fucking stupid and to buy real investments and make real money but then refused to elaborate.What should I throw 2700/month against /biz/?