It's hard to know what to look for when shopping for hair products or tools unless you have your stylist along with you. And with all the contradicting information about which is best, it's hard to know what's true or not!
After being in the industry about 10 years, I've had my share of experience with styling tools, and seen what lasts and what doesn't. I've learned that as technology improves, so do our tools, so investing in the right one will be totally worth it.
First, lets break down what words are commonly affiliated with styling tools (both curling and flat irons)
Ceramic: I remember when tools started to become ceramic. It was a step up from simply being "ceramic plated". Ceramic irons produce even heat, as opposed to a pulsating heat, that should maintain a steady temperature well. It's gentler on the hair than traditional metal plated irons.
Tourmaline, or Tourmaline Ceramic: Having a tool with tourmaline in it almost always means it will heat up rather quickly. It's a mineral that produces negative ions when heated up, and leads to a smoother cuticle in the end.
Chrome: Chrome is probably the most popular metal of choice for creating styling tools before ceramic. It's quite hot, almost cooks the hair, and does not produce even heat. In general, it should be avoided.
Titanium: Titanium is lightweight, heats up quickly, and maintains an even heat throughout the use of the tool. It's found mostly in high end irons.
Gold: A lot of Hot Tools irons are gold-plated (typically 24k), which means they get hot and stay hot. They also typically have a heat dial which allows you to control the temperature (very important feature) so you don't do excessive damage to the hair. While I'd still say Ceramic or Tourmaline is better than Gold, Gold is not bad for your hair.
So if you are shopping for a new tool, look for descriptions using words like "ceramic, tourmaline, or titanium". These will be high quality, produce steady heat (so you don't get the weird wavy look on flat ironed hair) and should be rather durable.
My favorite flat iron of all time is the GHD 1'' (both classic and professional are great). After spending money on 4 Chi flat irons for my business, and watching them all fall apart, I finally invested in a GHD and have been happy ever since. Although Chi is probably the most popular flat iron out there, it is not the best. If you own a Chi and are happy with it, keep using it! If it breaks, instead of replacing it with another Chi, look into purchasing a GHD.
My favorite curling irons are Hot Tools. I'm still using the curling irons I received in beauty school from Hot Tools. They heat up quickly, have not chipped at all, and are absolutely essential for any bride or bridesmaid 'do. I've also used Babyliss, and I've been pretty impressed with their curling iron as well!
As far as inexpensive tools go, I can't recommend based on experience. The only "cheaper" iron I've used is the Hot Tools 1 inch flat iron, and I was fairly impressed with the capabilities. It doesn't come close to GHD, but neither does the price!
So when you are shopping for a new tool, make sure you look at what it's made with. And check with the store on their return policy--oftentimes you can return tools even after 30 days of using it.