Round trip flight tickets from Amsterdam-Tbilisi on Turkish Airlines were around 330 Euros (I booked 1 week ahead) and if you book early, you can get away with 250 Euros. In Georgia, I always used the public transport (buses, trains, marshrutkas, shared taxis and metro). Public transportation is very cheap in this country! For example, a metro or a bus ride in Tbilisi will cost 0.5 GEL, shared taxi (4 people) from Tbilisi to Kazbegi will cost 15 GEL each (distance is 155 kms), night train in a 1st class compartment will cost 28 GEL (8-9 hours journey). The marshrutka rides are also very cheap like a ride from Mestia to Kutaisi was 30 GEL, Kutaisi to Borjomi was 10 GEL and Borjomi to Tbilisi was 10 GEL. Marshrutkas can get very crowded and sometimes are very uncomfortable (depending on the type and condition of the vehicle).
I try to couch-surf when I am backpacking and even though I wanted to use couchsurfing in Georgia, I ended up using paid accommodation. I met a few local couch-surfing hosts in Tbilisi to show me around the city which was a great idea. I found out that couch-surfing is popular only in the big Georgian cities and not in the mountains of Svaneti or Kazbegi. I stayed only in hostels and home stays and they were all very well-maintained and had very decent prices. My city accommodations (Kutaisi and Tbilisi hostels) were around 25-30 GEL every night for a single room (breakfast included) and everywhere else, I used home stays which had all meals included (typically ranges from 40-50 GEL every night for single rooms).
Tbilisi – Sky hostel in Tbilisi. Tbilisi has many cheap options in booking.com, but if you prefer to stay out of the tourist trap and see how locals live, then you can book an AirBnB. I didn’t want to stay in the touristy old Tbilisi city and my hostel was actually a real house (not hostel) and I was surrounded by only local Georgians. It’s run by a Georgian woman who is very nice and is very close to the Marjanishvili metro station. I paid 30 GEL for a big room every night (single occupancy). The old city is very noisy with some bars playing loud music till very late night and I was glad that I didn’t stay there!
Mestia – Nino’s guesthouse in Mestia. You can book this via booking.com, but I preferred to first look around a bit before heading here. There are many other family run guesthouses in Mestia to choose from, but this has the highest ratings because Nino speaks good English (unlike Russian and/or Georgian in other ones) and she has a lot of contacts. This is why I could go to Ushguli because she grouped up people and we could share the marshrutka with 7 people which is very very rare in an off season when there are almost no tourists! It was 50 GEL with 3 meals included.