Like most outdoor pursuits, you need a lot of stuff for backcounty skiing. Between hard goods and soft goods (and tutus) you can expect to spend anywhere from $2,000 to $12,000 to get outside. Yikes! Since you really do need all of this stuff, here's a handy guide for where to spend, where to scrimp, and where to find the gear you need (assuming you live in the greater Seattle area).
And if you're completely new, check out this Backcountry 101 post outlining the gear you need and how it works and my post about How To Get Started Backcountry Skiing.
Where to spend:
BootsMost people think about skiing as a leg-intensive sport, and it is. But it's also a foot-intensive sport. You control your ski primarily with the stabilizing muscles in your feet. When your boot fits well, your skis will be responsive to these micro-movements. When your boot is too big, your foot will work to control your skis to little avail. When your boots are too small.... well, we all know how that goes down.
Buy new boots. Just do it. Spend the money and get what you want. Most boots these days come with moldable liners (and the bootfitters will do this for free when you buy in-store) and all boot shells can be "punched out" if they squeeze you in specific places. Do buy boots that feel pretty good on your feet already, and do have them molded and fit by a professional. I also recommend spending the extra money to get custom foot-beds, but these aren't necessary. Do not buy boots that don't feel right on your foot expecting to "punch them out" to comfort and just don't buy used boots unless you can remold the liners and are planning to buy custom foot beds.
BindingsLike boots, bindings are expensive. They are also heavy, and the type of binding you get will directly impact the level of fun that's achievable in the backcountry. Unless you plan on primarily skiing in the resort and doing only a little sidecountry action, do not get a hybrid touring binding. You want a straight up, light-weight tech binding like this one from Dynafit.
I know, I know, there's like a $100-$200 difference between the two. Let me put it this way: think about the moment when you're outside in the snow, completely wallowing. How much would you pay in that moment to not be suffering? Forward that money to today and buy the binding that weighs half as much. Tech bindings are easier to tour in, easier to carry, and don't freeze up and refuse to lock into ski mode the same way hybrid bindings do.
Waterproof/BreathableLiving in the Pacific Northwest, where it will rain while you are skiing, having gear that is waterproof is a good idea. The catch-22? You also want it to be breathable. This is so you can sweat under your clothes while it's raining without creating a rainforest inside your coat. At some point, you will just be wet, but the longer you can stave off that reality, the better.
Pick a few key pieces of gear and spend more for waterproof, breathable materials. Start with your jacket, ski pants, and backpack. If you're feeling ambitious, throw gloves/mitts in there too. The good news is, you can buy this stuff used. Make sure to follow the care instructions and treat your outwear regularly with Nikwax.
Where to skimp:
SkisSkis are like cars - the second you "drive them off the lot" you lose half the value. And like cars, they deteriorate over time but can last a damn long while with basic care. Scour the "Where to buy" links below for used skis. Be sure they have been well maintained. Avoid skis with huge, unrepaired core shots, rusty edges, or skis with multiple previous owners (as that means the skis have probably been drilled more than once for binding mounts). You get bonus points if you can find skis with bindings and skins cut to match!
PolesSeriously - you do not need fancy poles. You can get fancy poles, but you don't need them. Go to Goodwill and find some that fit you, or buy them used at the end of the season from a demo shop. Collapsible poles are great for long, multi-day trips and are conveninet for packing the car, but you don't need them. To find poles that fit grab a pair, flip them upside down, and grab with your hand right under the basket. If your arm is at a 90-degree angle, the poles are the right length. You can use your trekking poles for skiing too - just swap out the trekking baskets for bigger powder baskets.
Soft GoodsLike poles, you do not need fancy soft goods. I wrote an entire blog about how to layer for the backcountry, and any of the layers I reference can be bought at a steep discount. Right now (mid-February) is a really great time to score deals at your local retailer (on things like ski socks, long underwear, fleece, jackets, pants, and, my personal favorite, down booties). Go out there and knock yourself out.
Were to buy:
Yardsale section for deals on everything from skis and skins to packs and poles.
Yard Sale forum to buy and sell gear. Keep in mind the geographic reach of both of these sites is broad, so you may end up paying for shipping or driving far distances to pick up the gear.
Mountaineers members get a discount.