Bedding is expensive yes, when you fill a 120cm cage 10" deep! I have used the Aura and I have to say it is quite awkward doing a partial clean with 10" of bedding, through the front door (and you don't really want to be taking the top off as that's a pain). Whereas a 150cm tank would be easier - you do everything from the top (providing you don't have a bad back! But it could be sat on a coffee table eg so not at ground level).
I use Fitch paper bedding in the 70litre bags. It's not as cheap as it used to be and it's annoying they don't do the bigger bag like they used to. They do have a bigger bag but it's strips of paper rather than pieces, and that's a bit stringy for hamsters.
So a 70 litre bag of fitch is about £32. It would fill the base of a plaza 120 6" deep and pressed down. So you would need two bags of that to have deep bedding in a 120cm cage and maybe 3 bags in a 150cm cage.
So you'd be talking about £100 to fill a 150cm tank style cage with 30cm of bedding. But - the thing is - once it's full - you don't need to buy bedding very often after that

Most of the cage stays clean and dry and you just spot clean out the pee area. Then maybe every three months you would do a "third" cage clean. With a 150cm cage it could be a "quarter" cage clean. ie you do it in sections - one quarter at one end. Then maybe three months later, the next quarter, and so on.
So over a year you would maybe need one or two more bags of Fitch - because even when doing a quarter clean, you would still replace about half the clean bedding. The only unhygienic thing is their pee.
Wood shavings aren't really recommended due to them being softwood. Some people use the Chipsi wood shavings which are part spruce so less phenols in them.
Fitch 70L Paper Pet Bedding Bales size are 500mmx440mmx330mm Fitch Pet Bedding. It is very absorbent,may vary in softness and colour, our bedding is warm and is ideal for dogs,cats,rabbits,hamsters,guinea pigs and many other animals. The paper is shredded into small pieces of about 15-20mm...
www.fitchfirst.com
Personally I wouldn't just use all Chipsi - but you could mix it half and half with Fitch
Chipsi Classic Pet Bedding - the wet dog food you've been looking for! Buy from 5.99 £.
www.zooplus.co.uk
So basically - the more bedding you have, the less often you do any clean outs and never do a full cage clean in one go. Less stress for the hamster and less expensive long term - but initial outlay is expensive.
Oddly that Chipsi link talks about wet dog food!
