You can stay at a hostel..there are loads of budget options available. please check them online. Do visit lake pichola, fatehsagar lake, city palace, jag mandir, saheliyo ki baori, hathipole market,jagdish temple.
Volvo - 1200 INR per side
Hotel - A decent Airbnb will costs around 1500 per night
Food is pretty cheap. 500-1000 per day depending upon your eating choices.
Sight Seeing expenses- 1000 per day.
If you are looking for budget trip then travelling in train from Delhi would be there best option, Chetak Express and Mewar Express are the best trains available, it takes around 12 hours to reach Udaipur City Railway Station from Delhi, train leaves from Hazrat Nizamuddin Railway Station at 7 PM in the evening and reaches Udaipur at 7 AM in the morning. The rail fare is around 1k-1.5k for AC 2nd Tier. Places to visit during day time : Sahelio ki baadi
Nehru garden(fatehsagar)
Ambrai ghat
City palace
Gulab Bagh (garden + Zoo)
Jagdish temple
Fatehsagar Lake Places to visit during evening till night Karni Mata temple (sunset point ) 2 ways to reach either by Ropeway or by stairs. I prefer stairs coz it gives a schematic view of Lake Pichola.
Lake Pichola
Sajjangarh (Moonson palace)
Gangaur ghat ( behind Jagdish temple). I suggest you hire a bike coz every place is not far than 5 Km from each. Public transport is ridiculous & car hire will cost you more. Good Luck!!!
Happy Travelling!!
To visit the entire city you would require 4-5 days and with a budget of around 10-15k to and fro from Delhi including hotel stay. if your budget is less than this then you can go in for cheap and nice home stay options as well.
Happy travelling!