This roof-box is the best value for money on the market in my opinion. At 380 litres and 2m long it is big enough to hold the (cross-country or alpine) skis for a whole family plus a substantial amount of luggage. It is well made and light (one reasonably fit person can lift it onto or off the car roof) but quite rigid, with good aerodynamic profile giving minimum wind noise at motorway speeds. The central locking was quite stiff at the beginning, but was working freely after a few days of use. I got mine for £165, but the price has risen to £173 now.
Competitors are the Thule Karrite Roof Box Odyssey 360 Litre, which costs about £13 less, but is 10cm shorter - which would NOT fit x-country skis for anyone taller than about 175cm. The Thule Motion 600 Ski Roof Box 320 Litre, not sold by Amazon (out of stock), is about £83 more expensive, has lower capacity and is also 10cm shorter, so of limited use for tall x-country skiers. The latter does have the option to open on either side, which is slightly useful but not worth £83 extra.