Hey , I have a small suggestion to give , I will not suggest any travel company because they literally charge you double of what really costs. do your own research and bookings because travelling in italy is not that expensive. check my tripoto blogs or instagram ( explore_with_mohini) , ping me if you need any help in that .
Last year i went on trip for Nainital, Corbett and Mussorie for a week there are many hotel with less than 1000 rs but it not available Online you have to go there and select last year we went to Hotel Prince in mussorie.
If you are familiar with hindi then watch "Mountain Trekker" "Nomadic Indian" "Tanya Khanijow" "Desi girl Traveller" " Radhika Nommellers" "Dr.Yatri" these are some of the best travel youtube chanells
Spiti is best in every season. it's depend on you what do u want to experience.. for snow capped mountains try winter expedition otherwise visit in July or August..