I would think the reason behind Thomann's pricing is likely to be that Quilter have, or are in, the process of shifting amp production to China, they posted about it last week on their FB page, it's to ensure the long term survival of the company as they are sharing qsc's facility at the moment, they also stated that quality will remain as is and not be affected in any way.
Whatever, the Bass Block is a monster of an amp, it doesn't want for anything compared to any of my other amps, if we're travelling any distance to a gig or going in a car it's usually what I take, it sounds immense through the Four10 or the Dubster.