It's difficult to say - a lot depends on the packing.

As an example, I've been shipping a few empegs recently. All had identical outer boxes.

1) Original empeg inner box, bubblewrap and cardboard between the boxes - 6lb 8oz.
2) Original empeg inner box, foam peanuts between boxes - 5lb 10oz.
3) Non-original inner box (smaller), foam peanuts - 4lb 15oz.

That's a pound and a half difference based on packing alone. It's clear that the weight of cardboard dominates the packing weight, so the size and construction of the boxes has a large effect. These units were well packed in reasonably large sturdy boxes - I doubt anyone would be going larger/heavier. I'd suggest that the 2nd scenario is a good indicator. Note that none had sleds in so you'd have to add that weight.