Places where I stayed in 2017:

find good and cheap places in many touristy city's of Iran:
Hostel in Tehran - Seven Hostel - Cheap Hotel in Tehran
Iran Hotels in Tehran - Budget Hotels and Hostels in Tehran Iran

Tehran , B & B Teheran
Tehran Bed and Breakfast
save parking in the underground car park
a bit far from the city, 20 min. ride with the good metro system.

Isfahan
Ebnesina Hostel in Isfahan
Dorm bed US $ 15,- with good breakfast
Parking in a closed backyard

Shiraz
Raz Hostel
Dorm Bed US $ 15,- with good breakfast
no save parking in front of the house, but 500 meters away there is a parking with security guard 24 hours, extra payment!

Hamadan
Amady Hostel
Dorm Bed US $ 15,- with simple breakfast
Save parking in the garden

Bam
Akbar Tourist Guest House
very friendly and nice place.
Room price is always a bit of bargaining with him!
US $ 20,- … 25,-

Camping in some of the parks or picnic areas in the city's is always an option.
I tried it a few times and had some very good but also bad experience.
You will find some new friend there and they will invite you for dinner or tee.
But also it is very crowded with a lot of kids playing in the playground, bikes and cars passing by all the night. It will be loud and noise until 2 … 3 am. And after the families have returned to their houses the cleaning team and the Gardner comes to soak the the green grass with water. Not so nice if you try to sleep next in you tent! Make your own experience!

Hi, I had a great time in Iran, I traveled there last year, I stayed at Abbasi hotel in Isfahan the hotel was great, I booked it through 1stQuest website with a credit card.