As a Fannie Mae and FHA Multifamily underwriter, your replacement reserve should be based on the overall economic remaining life of the building. In other words, if the property has a remaining life of say 40 years, in theory you would replace most of the replaceable building components over that time frame. Using this formula and your 200 unit project, it would be safe to assume that at least 40% or more of the building components would be replaced. So---40%/40 years equal 1.0% annually of the new replacement cost. New replacement building cost is probably well north of $300/sqft. or $3.0/sqft. At a minimum your replacement cost would be around $3600 per unit.
Obviously, this would be cost prohibitive for most investments and so generally you see budgets that show capital accounts with large infusions staged over extended times. Additionally, most investment are not intended to be held that long and each subsequent owner recapitalize the asset/property extending the economic life of the building.
Quick word on replacement reserve - replacement reserve is for major systems, not normal wear and tear maintenance. Replacement reserve typically breakdown into three groups, mechanical (electrical, plumbing, hvac), structural (stairs, elevators, roofs, windows), foundation ( parking, grounds, sewers).
Unit replacements such as carpets, counters, appliances, paint etc..while capital expenditures, are separate from the calculations above.
All said - Most lenders prefer replacement reserve greater than $500 and usually rely on an physical needs assessment to determine cost over a 5,10, or 15 year period. FHA and loans over 20 years usually require substantially more.