Bitmain has traditionally used a "rollover" setup on pools, so that if pool 0 is down the miner will use pool 1 and if pools 0 and 1 are both down it will use pool 2.
 They normally autoswitch back to a lower pool number when it comes up, IME with the S5, but it might take several seconds to a minute to do so when it does so.


 IMO those folks asking $3500 are way high on their price - I could see charging $2000 as a "available now" surcharge but IMO $3500 is a blatant eBay-level ripoff.