I can confirm both the saving and that HMRC will refund the Danish VAT. I needed to provide HMRC with the exchange rate between the Danish Kronor and GBP for the date that the payment was made, and they accepted a printout from one of the well-recognised exchange rate websites. I also pencilled a note translating the Danish on the receipt to show clearly which element was the VAT.
Nice to see the saving is still substantial. Makes me wonder quite what's going on with the only UK supplier.
When it comes to replacement filters, I can recommend Jasun Envirocare: http://www.jasun-envirocare.com/ who will make custom filters that look absolutely identical to the Genvex branded ones, for around 1/3rd the cost, with the biggest cost saving being if you buy in bulk. I bought ten filters (five intake, five exhaust), or five sets of filters, from them for less than £100 including postage. The delivered price from the Genvex UK supplier was over £70 for just one set (one intake and one exhaust).........................