I DIY my own soft box 80cm x 60 cm and fitted them on 2 ikea lamps. That way, i can do great photo shoots without the space constraint. Cost me about $18 for both the lamps, box was free. Personally i feel lightbox makes the product "darker", so i just use 1 light angle slight on right of product and a secondary soft box on the left to fill the shadows.
However, the softbox by artworkphoto is foldable, so its neater but i think its about $60. Look at B/S section, maybe got people sell.