There are many green good places in India to visit. But the one place which comes to my mind immediately after seeing you question is East Godavari District of Andhra Pradesh. This district is the rice bowl of this state. Through out the district we will find paddy fields, cane sugar fields, coconut gardens. It is a viewers paradise. Konaseema a part of this district is a very nice area covered with lot of paddy fields, coconut gardens, mango gardens and cane sugar fields. The whole area is having very well laid roads with canals on both the sides of the roads. Paddy fields and coconut trees between the lake and the field. What a scenario. A viewers delight. When you travel here you feel you are in green. No pollution. One should not miss it.
Kakinada, a smart city, is the capital city of this district. Another city is Rajahmundry recently renamed as Rajamahendravaram. Both the cities are having good hotels at reasonable prices to stay in. Very good restaurants which offer very tasty food. Kakinada is very well connected by road and trains. Rajahmundry is well connected by road,trains and flights. All the areas of this district can be reached from these places by road in a reasonable time.
Kakinada beach, Uppada beach Hope Island and Bhavanarayana Swamy temple are important places in Kakinada. Hope Island can be reached by boat on sea from Kakinada. A delightful experience. Papikondalu , Sarangadgarametta, and cotton barrage are very important places to see in Rajahmundry. Papikondalu you have to reach by a boat. An awesome journey on Godavari river. Many Islands are seen on the way.
There are many piligrim centres in this district. Annavaram, Antarvedi, Ainavalli, Ryali, Vadapalli, Vanapalli, korukonda, Pithapuram, Bikkavolu, Samalkot , Gollalamamidada and Drakshramam are some of the places. You can reach all these places by road from Kakinada or Rajahmundry. Basing on the interest they can plan visiting these places. Taxis are available for all these places. APSRTC organises conducted tour to some of these places. Kadiyam is a place you find many nurseries . If you are in this place you feel green is at your feet. A beautiful place.
If you visit these places, don't miss, meals at Subbaiah's hotel, Kotiah Kaja in Kakinada. Coconut water at Konaseema, Tapeswaram Kaja and Palakova sweet at Rajahmundry.
If you plan a trip of 7 days you can complete the tour.
Coming to the expenses part once you reach this place the prices are reasonable and affordable by a middle class family once in a year.
I hope I have answered your points. All the best to you