Will that South Florida condo be a good investment?

I recently helped my mother sell her 2 bedroom condo in Palm Beach, Florida. Her building is on the intracoastal and was built in 1973. To update the property and comply with recent regulatory requirements, the condo association embarked on a multi-year improvement plan. The association financed this multi million expense obligating the owners to pay it back over several years. At closing, mom had to pay a little over $96,000 to cover the full assessment on her apartment. This was not a surprise. We expected it before she accepted the offer to sell. The buyer intended to do a gut renovation of the apartment and put it back on the market for 2x the price he paid. Investor buyers are looking for deals on older units because there are a lot of them on the market and if the condo has already passed the needed assessments to bring the property up to required standards the sellers are typically obligated to pay those assessments removing that risk from the buyer. The inventory of these now renovated condos in buildings that have been brought to “code” is growing across Florida. The question to be answered is how long will it take to sell them?