Student houses duplicate everything. Four people means four kettles, four sets of pans nobody uses, and a kitchen box nobody needs to move twice. Before anyone packs, walk the shared rooms once: agree whose kitchen kit travels, whose stays or goes, and do not pay crew hours to move duplicates to a new house that already has them. The same goes for the textbook pile and the clothes rail: what is genuinely not coming is decided before the day, not discovered during it.
Pack once means pack properly the first time: boxes closed and labelled by person and by room, bags tied and named, the desk emptied rather than carried full. A room packed before we arrive is a room moved inside the minimum. A room still being packed while the clock runs is how a £140 job becomes a three-hour one, and no crew size fixes that.
The boxes maths, at the published extras prices: boxes are £5 each, protective wrap is £15 and tape is £10 per roll. A typical room takes five to eight boxes, so £25 to £40 of boxes, one wrap for the monitor and the mirror, and a roll of tape between a house. Order what the list says, not a bundle built for a family house, and if you would rather use your own bags and borrowed boxes, that is fine too: what matters is that everything is packed, labelled and staged before the clock starts.