I was informed that the downstairs unit was flooded about 3 years ago from a water leak and there have been a few other minor water-related issues as well. 

That includes items such as a bigger water meter, work in public space, updating the energy efficiency, fire sprinklers, and so on.

When doing the inspection the tenant said not long ago there was water in the basement up to her ankles but was fixed recently.

They're especially great at putting the fear of God into you that if you don't use a "professional" to do the work, oh, water could get into siding, and cause serious damage, and no, no, no, you don't want that...They also offer the outside trim ("zero-maintenance") wrappers for the windows that you would want a bender brake to make.

Biggest issue to me would be water intrusion/mildew and the accompanying smell.

The two member condos were just formed to sell two dwellings on one lot and maybe share one water meter.

Simply bolted onto concrete flooring with no foundation perimeter to address water intrusion issues when it rains.

All of them have a lifespan, Roofs, floors, hot water heater, appliances, hvac, bath and kitchen remodel, etc.

Questions:Have your tenants been okay with the staining and slight smells of this water?

You have to use money to give the seller "moving money", money to bring the loan current if they are behind, money for title reports, money for escrow, money for advertising, money for making the payments after you take ownership, money for repairs if needed, money for cleaning the property, money in reserve in case everything falls apart (just to mention the big ones, there are also Insurance, water, electricity, power, property taxes and so on).