IWS valet service costs only a few dollars per bench, per month - a bargain as far as most residents are concerned. It's even better if you include a slight mark-up strategy - and use the extra income to offset the cost of compactor disposal fees. The service pays for itself. ROI Worksheet Calculate your annual Return On Investment (ROI) using Invisible Waste Services ROI Worksheet. Type of Unit Number of Rental Units Bench Mark-up per Unit ($ Amount) Annual ROI 1 Bedroom 2 Bedroom 3 Bedroom 4 Bedroom Annual Compactor Repair ($) Annual Pressure Washes ($)       Annual Bulk Pickup Charges ($) Total Annual ROI