PRICES IN GEORGIA
Generally speaking, Georgia is a cheap country to visit. Sure, you cannot travel for almost free as in some countries in SE Asia, but you still get pretty good value for your money. Compared to Western Europe or the USA, prices are in general about half as high and they are some 30% lower compared to Slovakia, my homeland. The official currency is Georgian lari (GEL), exchange rate is 1 euro = 2,5 lari. Average monthly wage is 400 euro. Speaking of prices, I will cover just a few areas relevant to tourists.
Food
Cheapest street food (khachapuri, lobiani, churchkhela) costs 1,5 - 2 GEL for a piece, in areas adjacent to Turkey you will find numerous shawarma stands with prices starting at 5 GEL.
If you want to eat in a restaurant, you can get basic dishes (khinkali, khachapuri) for as cheap as 5 GEL. I usually use the price of khinkali to quickly determine how expensive the restaurant is. One dumpling costs 50-60 tetri at the cheapest places, 80 tetri to 1 lari in better ones and probably even more in places I don't visit. If you want something more special, main dishes in standard restaurants usually cost from 8 to 15 GEL.
Last thing I wanted to mention - if you are staying at the guesthouse, you can usually order also half or full board from your host - price of one meal is usually 10 GEL for breakfast and 20 GEL for dinner. I strongly recommend to take it. Not only is this food homecooked, but it's usually much more filling, diverse and overall better than dishes you would have gotten at the local restaurant for the same price.
Accommodation
If you are on the budget, you will spend most of your time in family-run guesthouses or hostels. One night here usually costs 15 to 20 GEL per person. You can expect hot water (to some degree), usually wi-fi and sometimes also a complete stranger in "your" room.
Private rooms at cheaper places usually cost from 25 to 40 GEL, if you want to share it with friends, it's naturally cheaper than if you sleep there alone.
In developed regions such as Kazbegi or Svaneti, you can also find modern hotels with the high standard of service and developed prices, ranging up to 200 or 300 GEL for a night. The opposite extreme is so-called "garden camping" when you camp in someone's backyard and can use his toilet/shower. It costs 5 or 10 GEL and can be an option if you are on a tight budget.
And, of course, if you are on a really tight budget, you can camp. Personally, I wouldn't do it city parks (even though I saw few such people), but in more remote areas it's completely fine. I am not aware of any rules which forbid free camping in any Georgian national park (pls correct me if I'm wrong).
Of course, it's always better to hide a bit, don't camp right on the trail or too close to someone's house. Also, if you are close to village, I recommend to ask the locals (out of respect) if it's ok to camp there. They never said no.
Transportation
Regarding transportation, Georgia is quite cheap country. Most tourists use long-distance minibuses (“marshrutkas”) travelling between major cities/tourist spots. They have 15-20 seats and usually depart when full or when driver decides, that he collected enough money. It’s hard to speak about prices without becoming too specific, but in general, 1 hour of travel in them costs between 3-5 GEL.
If you want to travel a shorter distance, you can try local buses. They are very cheap, but also old, rusty and slow. If you are not travelling alone, it’s usually more convenient to take a taxi than local bus. Their prices greatly vary - they don’t have meter, so don’t be afraid to haggle. You shouldn’t usually pay more than 1 GEL per kilometer.