There are lot of euro-trip packages on coxandkings and so many others they are quite cool. check different itineraries according to places you want to cover and if you dont want to be a part of group tour its always better to get a customised tour
The best way to travel in Europe is book hostels... You can find a bed for a person at around 30-60 euros / night. Also, the euro rail is a very convenient option to travel within countries. Hostelworld.com for hostels and goeuro.com for the trains.
Hey Vidhi, For a budgeted package, you can visit www.tripoto.com... They can suggest you the best package as per your requirements... Happy Travelling!!!