Might be a fair price with a return policy like that. No completed items on eBay, so I don’t know what the used ones are going for. The ones listed with a day or two left are around $1000. Who knows what they’ll sale for and there’s not usually a return policy. With 3 months to return it, you’re safe if you change your mind – I’d say go for it, take it home and see what you think.
OTOH, there’s lots of other great mics that can be had for $1500 and under. Brauner Phantom C ($1500), or Soundelux U195 ($1150) come to mind, Or, for $350 more, the Soundelux ifet7 ($1850) which is like having two high caliber mics in one! If I had $1500 of microphone money burning a hole in my pocket, I’d save up the extra $ and get that one. Way more versatile than the U87.