Audio is often overlooked by newcommers to videomaking, and it's one of the areas where your video can appear very amateurish right away no matter how pretty the visuals are.
A solid shotgun microphone is essential to your gear, if it's just you and no dedicated audio guy, it's shotguns and lavs that will get you good audio when used properly.
The AT897 is in the budget category coming in at under $300, but its performance if used properly is very nice. What you won't get with this as compared to a higher end mic, is the ability to retain the dynamics of the sound when the mic is farther from its subject. My AT4073a cost twice as much as the 897, and sounds notably better when more distant that preferable to the subject. Sometimes you just can't get closer, and a higher quality mic helps. Keep in mind the other tools to remedy such a situation are lavaliers which you can hide on the subject, or cheat by using the audio from your closeup shots in your wide angles. Doesn't always work, and you should plan your angles accordingly.
But when this mic is within a reasonable distance from your subject, it has a nice warm rich sound. It's fairly good at off axis rejection, but again, not quite as good as the higher end units.
The build quality is very good, mine accidentally got hit by a ceiling fan and it survived no problem.
The built in AA battery compartment solves the phantom power issue if your camera doesn't have that for some reason, but it does make this mic a bit longer.
Overall, if you're just starting out there are a few options for lower budget shotgun mics, this, and the Rode NTG series