My first pass was just about price, but I ended up paying more attention to where the hotel was located. A cheap room can stop looking cheap once you're adding long cab rides every day. I checked this against a couple of separate bookings and the affordable Goa honeymoon tours option here gave me a useful baseline. From Mumbai, I'd also compare flight and train costs before deciding on dates, since Goa is easy to reach but fares still jump around holidays. Monsoon rates looked lower in the examples I checked, although I'd want a backup plan for rainy days. The itinerary isn't flawless, but it gave me enough detail to make a more sensible shortlist.