Denis,
Yes they do.
The biggest (and best?) caravan / motor-home / camping / outdoor shop in Europe is Camping Sport De-Wit just South of Schijndel, between 's-Hertogenbosch and Eindhoven.
70,000 square metres of bits and bobs - that's more floor space than 12 football pitches.
web-site www.de-wit.nl
I work in Rotterdam and make one or two pilgrimages at the start of each season, and a visit for the end of season sales in September. Even out of the sales, normal prices are 1 Euro = 1 Pound - so it's possible to save 40% on nearly everything.
The only downside for someone in the UK is the cost of P&P - so a day trip when on summer vacation is a possibility.
Robert