Athens

What is your interest? Museums and antiquities? There is more than enough to do for 3 days - Parthenon, National Archeological Museum.

Do you have the RS Athens book?

We would like to do historical sites
Would a trip to santorini be possible
What about nafplio

Based on your other posts, you do have a predilection for a brisk pace.

There is a 910 PM flight to Santorini, so if your flight to Athens is on time you could continue on directly to Santorini. Return to Athens on the 28th and see a few of the major sites before your departure on the 30th.

Ha ha all our trips are time and money sensitive
thanks for the inputs

The way to save time and money is not to spend them on further travel beyond Athens. Visit the Acropolis, the Acropolis Museum, the National Archeological Museum, the Agora, Syntagma Square, the Plaka and Monastiraki areas, the Cycladic Museum, the Benaki Museum, the Kerameikos site and museum, and/or other historic and cultural attractions. Most of them are within walking distance of each other, and the Athens subway is convenient (take pickpocket precautions). Invest in a guidebook like this one to help you choose among the above and more.

Stay in Athens! Save the travel time and $$. If you can't find things to keep you entertained for 3 - 4 days, you aren't looking. After the Acropolis & the museums, wander the Plaka, visit the Monastiraki area, go to the Central Market. Save the islands for when you have more time, They are not for rush-rush visits.

I agree with larry42. The fish market and meat market are fascinating. The flea market is very interesting, too. Watch the Changing of the Guard at Parliament.