I think DIY gives you extra flexibility, we too are doing an unusual amount of nights 23 as we have tagged the Easter days on the end of the normal 3 weeks.
I don't think we will save a lot of money but we are not doing it cheap and will get better value for money and have, you can choose the day you want to fly, include a Mumbai visit on either your inbound or outbound flight (we are staying 2 nights on the way back where as last year we visited during our 21 nights so lost valuable sun days!!)
The down side is you have to pay in advance for your flights,
I just did the Google and found a choice of appartments, then trawled through the flight brokers.
I certainly have undercut the price of 3 weeks at the Marinha Dourada our last 2 visits and have the extra days, large appartment, better flights
Mids