Have you ever thought of buying a car for your trip and selling it later again? It's definitely worth to consider it, especially if you should travel a bit longer.
You will save some good money!
You just shouldn't crash it, but that's something you never should do, right?
First of all you should know how much you can invest. You will see that you can get really cheap cars, but these are sometimes also a bit more risky. Usually, the cheaper they are, the more you've got to invest later.
But you should always expect some repairs at any time. That's why I would recommend you, to choose a popular brand. It will be easier for you to let one of them to be repaired, as spare parts are easier to get (perhaps even cheaper) and more common.
Save on accommodation costs:
Ever thought of using your car as a camper van? Buy a big caravan and you should be able to put a mattress in the back. If you think that it takes too much room, then a big air mattress should do the job. You can buy a big air mattress for about $20 and for another $20 you'll get an air pump which works with your 12 Volt car plug. Sleep in your car twice & you have the costs in again.
Where to buy and sell a car:
With the www it's much easier to buy and sell your car. You should be able to find quite quickly good sites for the different destinations where people sell/buy cars. Usually local newspaper have sections for it as well and also online.
That's also where you could try to sell your car. Add it soon enough! You could say in the text, that you will be in destination X at a special date to sell it. Expect not to get the same amount back, which you have bought the car for. But it should be still much cheaper than renting a car for 2 months or longer.
If you don't have that much time for your journey, it's also worth of thinking to rent a car, because it takes more time to buy one and to sell it later again.
You also have a lower risk, if repairs have to be done with a rented car. The rental station will pay for them, if it's not your fault. Have a good look at the rental contract for these things!
At the moment you are travelling for a period over 2 months, its worth buying a car. Remember, if everything goes well, you'll get most of your money back with selling your car again.
Sure, you would like to sell your car for a higher price than you bought it, because you had repairs on it or other costs. But if everyone would do it like that, most of the cars you'll find, wouldn't then be payable anymore.
At the moment you've rented a car, the money is gone, of course.
What to look for when buying a car:
Take a good look at the car and especially underneath it and also open the hood. Believe it or not, but we've heard of a story, that two travellers bought a car without an engine.
If oil is leaking out of the engine, leave your fingers of this car and better take another one!
Make a test drive and listen for strange sounds!
At the moment you've got your car, you will probably drive a lot of kilometres with it in a short time. Then you should change your oil and the filter every 5000 to 7000 km! Your engine will thank you! It's quite easy and much cheaper if you do the oil change by yourself.
Registration & Insurance
This is of course different from country to country. In Australia and New Zealand for example, it's quite common for travelers to buy & sell cars. You might need a permanent address, but why not use the hostel's address for that.
Your automobil club (AAA) or the one of the destination which you'll explore, should be able to help you what exactly is needed. It will be an uncommon request for them, so give them a hard time and don't give up too early, also if you get told it's not possible to buy a car as a traveler. Usually there are always ways!
In the end you have saved on accommodation costs and at tour and/or transporation costs. Maybe take other travelers along. That way you meet some great other travelers and you could split the fuel costs.