I got a feeder at a Petsmart because I drove by the place on my way home. This linked one isn't mine exactly, but the features are pretty much the same.
Glass reservoirs hold up longer and are better to resist mold and solar discoloration. Feeders almost HAVE to be red, because it is a known fact among hummer experts that the birds are attracted to the color. Doesn't mean they won't feed from another color feeder but they'll notice the red ones first.
It's dumb to buy nectar when you can make the stuff yourself easier and much cheaper. Every reference I've ever seen (on the Lounge and in the real world) gives the exact same 1C sugar and 4C water mix recipe. But this sugar water will ferment or get fungus-ey after a few days, so unless you want to harm the little ones or run them off, change the solution every three days. Which again makes it far more sensible to cook your own hummer 'shine.