The metrol rail is cheap. I’d consider buying a week’s ticket on the metro which runs for roughly 25 euro.

I think it’s safe to say that you’ll be spending about 100 euros per person per day minus your hotel stay. We were able to do this and it covered our event fees, café stops, light brunch/lunches and a good dinner. We also tried walking to/from as many attractions as possible, which allowed us to stay within budget and buy more souvenirs.

I imagine you’ll be visiting some museums in that week, so I’d get a museum pass, which is roughly 30 euros. You can also buy a carnet of 10 metro/bus tickets for 11.10 euro. Last time we went we averaged about 3 tickets per day per person.