The roof is around 25 years old, and will likely be replaced upon purchase.

I'm thinking that the plumbing and electrical would be the two most critical pieces that would need replacing in the near future (and of course appliance upgrades).

Whatever entity sells the property needs to buy the replacement properties.

Which reminds me - it's time to replace the filters!

If you're financing your deal with agency debt, there's a very good chance that the lender will require you to provide at least 12 months worth of debt service at closing (Fannie Mae will likely also require at least 12 months worth of real estate taxes, insurance, and replacement reserves at closing). 

I pulled out of a contract on a duplex built in 2000 after inspection shows an immediate need to replace the 20yrs old shingle, HVAC, and  some other minor electrical.

They had a guy out when they gave me a quote and would only do full replacements.

So flooring, screens, door jambs, etc will be repaired or replaced if  damaged. 

When the roof on the building needs replaced, everyone pays for it, even if it's only damaged on the opposite corner from your condo.

For example, replacing a ceiling fan is the same cost whether the house is worth $50k or $500k.