Seriously, I'm a neurology resident and I look in eyes all day long and I don't even own an ophthalmoscope. My advice would be the following: I
1. If you are going to work in a really destitute hospital where no one can EVER find an ophthalmoscope, then think about buying a cheap one.
2. If you are going into pediatrics and diagnosing ear infections 'til the cows come home, then think about buying a cheap one.
3. If you're so desperate for recognition that you're willing to carry around an extra 3 pounds of tools on the off chance that you get to be the "well prepared med student" just once, then think about buying a cheap one.
4. If you can envision yourself being the hero on the subway that correctly diagnoses a central retinal vein thrombosis in the woman sitting next to you when she suddenly develops transient monocular blindness, then think about buying a cheap one.
5. If you like scaring patients, or if you are going into ophtho, ENT, or neurology, think briefly about buying a Pan-optic, then blow it off and find yourself a residency that gives you book money for that sort of thing. Then take the money you would have spent and blow it all on hats.