Sure, Momondo has been around a long while; it was the first flight search engine when it launched back in 2006. It has since grown to be a well-regarded meta-search engine (like www.skyscanner.co.in or www.kayak.co.in) that collates and compares travel deals from airlines, online travel agents and flight data wholesalers, so you will do the actual booking via sites to which they direct you. Pricing will also depend on booking ahead, the airlines, and convenience in connections, so check those too.
You will find plenty of useful information on Stockholm’s attractions at www.visitstockholm.com. The Swedes are spoilt for choice when it comes to public transport; find out more about their Metro, buses, trams, light rail, rail and ferries at sl.se/en. The Stockholm Card (www.visitstockholm.com/en/stockholmcard) saves you money and time, especially if you spend three or more days in Stockholm. Sweden is a vast country, so one week simply isn’t enough. Assuming you want to focus on the north, and even this can’t really be covered in a week that includes Stockholm, head for breathtakingly remote Vildmarksvagen, the church town of Vilhelmina, the Unesco-protected splendour of Lulea, the magically beautiful High Coast, and one of the best places in the world to catch the Northern Lights, Abisko. Instead of budget hotels, may I recommend the economic advantages of fully equipped rental apartments? Once you have finalised your itinerary, look for cosy places to stay via www.stugknuten.com/defaulteng.asp, www.vrbo.com or www.airbnb.com. Sweden is an expensive country to visit, so expect to spend at least about Rs 8,000 per person per day, plus cost of Schengen visas (about Rs 4,300 per person), and whatever best deal you have on the flight tickets.