Im putting together a list of my 5 essential items that you shouldnt cheap out on, because Im kind of full of myself and think I know a lot about style. My main litmus test is whether or not its an investment. Take an expensive car, for example. Or really any car. It loses (at least) half its value the minute you drive it off the lot. You will never get more money for a car than what you paid for it. So if you can afford it, great, but recognize its just a vanity thing.
1) Good sunglasses. Expensive sunglasses. I think everyone should have one pair of really good designer sunglasses. People can tell the difference. Try not to get anything overly trendy, because this is an investment piece that you should be able to wear forever.
2) A really great handbag. A giant one that you can tote around a lot (if not all) your shit in. It doesnt have to be super expensive, as long as its good quality leather. Leather bags age very well if you take care of them. I have one of my mom's old bags from oh, 30 years ago, and it still looks good.
3) A really good hair dryer, and hair tools in general. Just like theres a big difference between 10 dollar foundation and 60 dollar foundation, theres a huge difference between good quality hair dryers and shitty ones that will fry your hair and make it dry and brittle. Also, good quality make-up. Your face is your greatest possession, and you get what you pay for. Make sure there is no mineral oil in anything you put on your face.
4) A great winter coat. Not necessarily expensive, just great looking and well fitting. This is something you wear almost everyday.
5) A good watch. As long as its mechanical/automatic. I have seen good ones for as little as 50 CAD on eBay. I have seen even cheaper ones on Craigslist and antique stores. Never spend real money on a quartz watch. It has zero collector appeal, and is basically money down the drain. Keep in mind that a giant plastic Timex watch is also always acceptable.