hair extension damage???

I am thinking of getting hair extensions, but I've heard all the horror stories and am scared that the extensions will ruin my hair and cause it to fall out.  But I have also heard of other methods that don't cause damage.  Does anybody know about extensions, and also what would be a reasonable cost.  I don't want to spend more than $600, and I would like 12-18 inches of hair.

[ms0323]

i had braided hair extensions in for 2 weeks, which were suppose to last 3 months, but i took them out because my hair was getting really dry and breaking off at the roots, i had them down to the middle of my back and it cost 260 to get done, they try to recommened all this moisture stuff for your roots and its a good idea to take them but there are alot cheaper things out there... thats my expeireence and everyones hair is different.. and they say it is suppose to make your hair grow faster but i find it just makes your hair thin and drys your scalp out!!