Thank you for sending in your travel question. I have done some research. Please find the results below. I hope the maximum price of 300 EUR is the maximum price per persoon, because then I found a good offer for the total amount of 704,85 EUR for two persons.
You can book the following return flight on https://www.transavia.com/en-EU/book-a-flight/flights/search/
The price for the return flight for two persons is 178 EUR.
07/10/2015 AMS - BCN 06.00 - 08.10 HV5131
14/10/2015 BCN - AMS 21.45 - 00.10 HV5134
You can book the following accommodation in the city centre on
The price for seven nights for two persons is 437,09 EUR.
You can book a Fiat 500 on
The price for this car is 11,22 EUR per day.
If you stay in the city centre, I would recommend not to rent a car, because travelling by public transport is more convenient and maybe even cheaper as well, because you have to pay parking fees if you drive your own car. Furthermore, you might experience difficulties finding a parking lot.
I hope this offer suits you well.