I have some experience with both the el-cheapo's and my new Costa-del-Mar's. I got my Costa's at an incredible discount so it wasn't so hard on my wallet and therefore an easier choice. Anyway, before you buy, ask yourself a couple of questions and be honest about reality when you answer. Do you take good care of your stuff, especially small things like glasses? If you're a bang it around kind of person, get a cheap pair. Do you lose things often or misplace them or are you one that keeps everything in its place? No use spending $300 on a pair of glasses you lose in a week. What type of fishing are you doing, sight fishing or just structure fishing, bottom/deep water fishing, and fan casting? If you aren't sight fishing, and don't plan to, polarized sunglasses will just be a nice thing to have cause of the protection they offer your eyes. If you are sight fishing, like in the flats for redfish, or looking for beds to cast on when bass fishing, or if you catch your own live bait, then the polarized glasses will be invaluable. They definitely help you see into and below the surface of the water.
Ok on to the price point. If you do your homework on the high $ brands, Costa, Maui Jim and others, look at how many different layers,coatings they put on their lenses, they aren't just polarized, but offer other protection and performance benefits. Look into the company's warranty policy and repair/replace rules. Call customer service and ask some questions to see how they treat you. And go and try some different models on your face. Not all glasses fit the same, some are just wrong for your facial structure and others fit like they were custom made for your noggin. A poor fitting great pair of polarized sunglasses WILL be worse than getting a good fitting cheap pair. Not only for your comfort wearing them ALL day, but a poor fit may let sunlight in to the back side of the lens and cause glare. Fit should not be too loose or too tight and IMHO, you'll want something that sheds some wind. You don't want to loose them running to a spot cause they fly off, I've had this happen when turning my head with a prescription pair while on vacation, not good.
Glass or plastic: Plastic is cheaper and lighter which is easier on the wallet and on your nose especially for all day wear. The big down side to plastic is the lenses scratch easily even if they say they have scratch resistant coating on them. It's better to have the scratch resistant coating than not, but the plastic lenses will begin to dull and scratch eventually, much faster than glass. Glass lenses, especially quality glass, have better visual clarity and will put less strain on your eye. You'll notice this at the end of the day when your eyes feel tired and seem to not want to focus as fast. They are MUCH more resistant to scratches and breakage and sometimes have more protective coatings than the plastic versions. If you take care of them, they will last forever, and if you buy from a good company, if they ever break, they'll fix or repair for little or no money. The down side to glass is the weight. Your nose bone may be sore at the end of the day. This will be exacerbated if you don't chose a pair that fits you well. In my experience, it's just a slight nuisance and worth it for the quality of the lens. By the way, either way you decide to go, LEARN HOW TO PROPERLY CLEAN YOUR LENSES AND FRAMES! Learn what NOT to use to clean and tell everybody that may try to help you or that may use your glasses, nothing like having someone try to help by cleaning your glasses with a brown paper towel.
For me, I have had a good track record taking care of and keeping track of my things. More of my glasses throughout 30-ish years, have been broken lending them to people, or from my kids, than from anything I have done. I did my homework and tried on about 50 different pair before deciding. I am extremely happy with my choice. Hope this helps.
