.daa is kept pretty locked down by Poweriso, in effect yes, making you have to buy it. Why people create files in propriatary software is beyond me other than that is what they had. After some more searching it looks like you'll have to convert it to ISO using either the program I linked to or another similar way (there are ways to upack and repack it to iso for free as well) the only other option you have is to buy Poweriso. It really sucks for sure though, I had a similar experiance before and I pretty ticked off about it.