Very rarely is an item truly rare and ive seen many listing every day with this word thrown around even on items that you see all the time or several in one go, some listings are not rare at all and is purely to make it more desirable, to make something rare in my opinion it would not be on google, i have had many items in the past that google didnt even recognise, never mind finding any info on the items, for something to be truly rare at the very least is not on ebay at the same time you list your item, but sometimes very rarely it may happen, like it did with me with a pair of bowers and wilkins DM6 speakers which are truly rare, dont be fooled into thinking somethings better than it actualy is by sellers using the words WOW/LOOK/RARE and 640 WATTS RMS AMPLIFIER!!!
One very important fact that i feel everyone should know about is concerning amplifier wattage, if you look on the back of any hifi separates amplifier and see a section where it says something like for e.g 240v 50Hz 500watts does NOT make this amplifier 500 watts music power like an incredible amount of people think it does, this is merely the power consumption from the mains voltage, it is in no way reflected in the amplifiers speaker output, i have a 1ooo watts hifi amplifier that only puts out 50 watts per channel, so if you see a listing with an amplifier that says it has over 200 watts power please be sure that this maybe what they have read on the back and definately not the speaker output power.
R.M.S is the worst measurment for amplifier output and does not mean anything apart from making an amplifier appear more powerfull then it actualy is, same goes for speakers.
If at all possible, ask the buyer what the continuous power output is which will give you a closer idea what the actual output is.
Lastly and most importantly, if you see a nice separates amplifier with what seems to only have 50 watts per channel then dont be put off, 50 watts is alot more than you think, the problem is consumers these days are led to believe that there small mp3 dock with 70 watts rms power is louder than that old rubbish pioneer amp thats only 50 watts on ebay, well i can tell you its not, the real wattage of that mp3 dock is only about 5 watts, proper watts and even thats being generous, again, the output is measured in R.M.S, an old pioneer amplifier for example with 50 watts per channel will easily power a pair of, for e.g proac response 3.5 250watt floorstanding speakers with mind blowing results, why? because they are sensitive and the amplifier will easily drive them, so dont go spending loads of your hard earned money on a very powerfull amp to match your speakers as this is not the case, if your speakers are over 90db 120 watts for e.g then a 25 watt amplifier will power them easily and very loud.