Chin Habitats
There are two kinds of chinchilla habitats: those with a lot of vertical space (height) and those with a lot of horizontal space (width). In America, vertical cages are the norm. Nearly everyone I know in America goes for height when it comes to their chinchillas' cages. In Europe, there is the idea that chinchillas are rock hoppers, not tree climbers, and so they tend to emphasize horizontal space. I have three tall cages because three of my chinchillas love to jump and climb. I have one horizontal habitat because that chinchilla loves to run around and make little hops.
The necessity for a large cage
Starting out, it seems like anything over $100 is a lot of money for a cage, but it's not much if you look're looking for quality. You have to remember that a chinchilla's cage is pretty much its entire world. Would you want to be closed up in a small efficiency apartment day after day for 10+ years? Neither would a chinchilla want to be closed up in a small space for that long. Get the biggest cage you can afford.
Vertical Habitat Examples
The absolute best cage you can get for your chinchilla is a Ferret Nation. They are $229 (plus shipping) at Ferret.com. While they are pricey, you will never have to buy another cage for your chin again. They are incredibly sturdy and well built. They're relatively easy to assemble, and you can leave the floor to the second level out without compromising the integrity of the structure. The front side is made of 4 doors. The most inconvenient thing about this is if you have an escape artist, you have to find a way to block the opening so he or she can't get out. They are 24"x36"x60" (counting stand with nifty shelf).

Mei-Mei's top level, one door open
Mei-Mei's bottom level, doors open
Cheel's top level, doors open
Cheel's bottom level, doors closed
If you're willing to put some effort forth, a Superpet home can be made suitable for chinchillas. Earnest Anselm used to live in a stacked Superpet cage. I bought two cages and attached them with j-clips that I got from the Tractor Supply Co. All in all, I spent about $170 on his cage. This cage measures 17" x 29" x 60". It does not have a stand, which is inconvenient, and the doors are small and awkwardly placed, but we trained him to jump onto our hands when we needed to get him out of his cage.
Earnest Anselm's top half
Earnest Anselm's middle view
Earnest Anselm's bottom view
Martin's Cages can also be made suitable with a little effort. Hypothetically, they are complete cages. They come with wire mesh shelves, a floor and ramps, at least. We do not personally feel comfortable using wire shelves. This discomfort was reinforced when Eva, after two weeks in her Martin's cage, snagged a toe between the shelf and the wall of the cage, spattering blood all over everything on the floor below her. We are hyper-safe, we'd attached the shelf every inch with c-rings, and she still got injured. Needless to say, we removed the wire shelves for wood that very night. If you use Martin's cages, we suggest either using c-rings every inch or replacing the shelves with wood.
Horizontal Habitat Examples
Pepper's habitat maximizes horizontal space. It is a Superpet My First Home for Chinchillas/Ferrets with a Marshall's playpen attached. His cage measures 17"x29"x30". With the playpen addition, his habitat is 48" x 48" x 30". I spent about $130 on his habitat. I put an old comforter on the floor and covered that with a square of fleece. We change that out every week. The hardest thing for Pepper's habitat was figuring out a safe cover. We finally decided on wire mesh we found at Loew's in the gardening section. It's 1" x 1/2" stainless steel and is sold for people to make pet cages.
Pepper's cage

The right half of Pepper's playpen attachment

A far-away view of Pepper's habitat
We used to have Mei-Mei in a horizontal setup, however she prefers climbing and jumping. She now has a Ferret Nation. Below are some pictures of her old habitat. She had an Extra Large Superpet My First Home with another cage attached to give her a loft. A Marshall's playpen was attached to her cage, and she also had a fleece floor cover. Her habitat measured 40" x 48".
Mei-Mei's old habitat with the shelves removed