- Each card should weight at most 1kg (heatsinks...) -- this is an overestimation, for reference an HD 6990 weights 1.16kg.
- The 1400W ATX PSU will weight about 2-3kg.
- The case and fans will weight about 10-15kg.
Therefore I estimate a mini rig will weight 30kg +/- 5kg, still kind of transportable by an adult in average shape
BFL said the mini rig weights a little under 23kg (50lb). I was close
https://bitcointalksearch.org/topic/m.966604