The whole you can't keep down compressed is an old wives tale. There was a study done on it somewhere but I can't find it for the life of me. I believe the only impact long term compression has is the length of time it takes to re-loft and reach it's full insulating value. I keep mine compressed, some for years and they are fine after a few hours of opening them. I also have my Grandfather's Eddie Bauer down bag from the 70's and it was compressed for 22 years and it's one of the nicest bags I own.
I'm hugely biased in favor of down, I don't think there is anything more comfortable to sleep with. I've owned at least two dozen different down bags, comforters, and throws. I also own several jackets that stay compressed year round and are only opened for above tree line hikes in the winter, they've kept me warm every time. Down is one area I can confidently say, the more you spend the better it is. If I could only have one brand, it would be Big Agnes, it's almost ridiculously expensive, but it's top notch, I have a comforter from them that has a sleeping bag style shell and it's hands down one of my top ten possessions.
To the OP, I say you will spend a 1/3rd of your life sleeping, buy the best quality bedding you can afford. If spending a few extra bucks, even a few hundred extra bucks on a top shelf sleeping bag allows you to spend a few extra nights comfortably in your car over getting a motel room, you'll make up the difference in no time, over a lifetime of motel savings, it will literally be making you money. Mine legitimately puts a smile on my face every time I use it. But i'm a gear junkie and probably get more joy from some of my gear than is socially acceptable!