in my view, buying properties is unlike buying cars, whereby the older the car, the cheaper it is.
Price of old condos will only increase at a slower pace due to competitions from nearby new condos.
What may suffer is the rental. Some tenants like newer condos for the conditions of the house and the facilities. Nevertheless, renovated units at older condos can still be attractive as the units may be bigger yet cheaper than new condos.
just my 2 cents worth...