in my book the jury is still out, if a trader with the use of gunbot can beat the market at all. with other financial instruments such as shares, bonds, etc. it may possible on short term. in the long term just buying and holding across the market wins.
this year, I am sure any bot trader will make a collossal loss with the bot against holding a sensible cross market spread (arbitrage trading not taken in account, but even that wouldn't brake the line). this is because of how the market played out plus the bot across all the versions displays various hiccups. on jan 1st 2017 total market cap was a little less than 18 billion USD, on oct 29th 2017 the total market cap was 170 billion plus USD. so the mrket gained roughly 940% this year until oct 29th. with a 20% per month gain you are way behind (this is what the author of the gunbot makes on average, and is nothing to be sneered about.) not way behind, way, way, way behind. and I have yet to achieve a 20% per month gain. so for me it is loosing me money against just buying everything across the market and holding. I have yet to see anyone gunbot trader with a gain of over 900% this year. so far not one bragged of these gains. or even more than 300%, if we take the BTC price gain of roughly 600% out of the equation. still alot behind.
better not to count bags that are eating profits away, and so are fees.
now, don't get me wrong. I never ever regretted buying this thing. I have a blast just looking at it go. I treat GB as a hobby, and as you know, every hobby has it's cost.
so, gunbot is not the stuff lambos are made of. lambos are made of cross market bundles, held for a long time. that's ma personal advice of acumulating wealth. or, make a better bot, with more than 2.500 licenses sold @0.1 BTC in todays money this is roughly a million and a half USD, in private transactions, untaxed I presume.
the disadvantage of buying a second hand bot might be a lenghty process of approval. a month is not unheard of.
how many people have sold their bot? count the WTS posts (it's some, not a lot, but some). they sold beacuse it's not a money printing machine, but they expected one and were dissapointed when it wasn't.
I would start with 0.4 BTC offers for a second hand, it's still the same, or even more than the bot cost in fiat if bought pre august 2017. so a fair price, because much more hassle for you, as if bought new.