For Sale Audio Research Ref 5

How much should i bid up to on a Audio Researh Reference 5 pre-amplifier which will be sold at my local auction house in UK.
The unit is brand new in its original box but there are no documents, certificates, cables or remote control.
The auction will occur on Tuesday at 10:30am and any advice before then will be much appreciated.
I am a private seller and was interested what people would be prepared to pay for one should i be successful in winning it.
you could sign up for and check what the typically sell for here on the Audiogon bluebook
Not sure how it can be brand new without any documents, cables or remote control, all of which come with a brand new unit.
Well without the manual and remote, it really can't be called "new" might want to change that to "mint". That said, I have been seeing them go for @ $7,000 USD.