Costs to add Washer/Dryer units on a per unit basis???

[Joey Budka]

Does anyone have any experience adding washer and dryer units to large apartment complexes? How much does it cost on a per unit basis, including, labor, materials, W/D units, etc.? 

Also, would be helpful to hear from investors operating within in-fill markets like Bay Area, LA, Boston, Seattle, NYC, etc., where labor costs are a big factor to consider in budgeting this out.

What are the premiums you're achieving versus units without washer and dryers?