"Dear" kann zwar durchaus auch "teuer" im Sinne von "kostet viel" bedeuten; aber der englische Beispielsatz scheint mir dennoch eine ziemlich altmodische, überförmliche Formulierung zu sein (bei aber Dt.-Muttersprachler und deshalb nicht total kompetent). Deshalb würde ich eine Neuformulierung oder Löschung auch befürworten.

I agree with gherkin; 'dear' in this sense is largely old-fashioned, and it definitely sounds quaint nowadays, probably even in BE. I suspect Mr. Honey was at work here.

'Goods' is also a bit odd when referring to real products, as opposed to economic theory. A modern businessperson would say something more like 'Unfortunately, your products are too expensive for us.'

Google: Results 11 - 15 of 15 for "we find your * too dear
(all quotes from Mr Honey)

"Dear" is still used to mean "expensive" in BE and isn't what I'd call quaint, although it is more old-fashioned, and not as formal or business-like as "expensive". It isn't a complete no-no, though:

"The Trade Minister, Brian Wilson, welcomed the record surplus in services, but his Conservative opposite number, John Redwood, said the trade figures were 'dreadful' and placed the game on the Labour government's policies. 'They have made it too dear to make things in Britain,' he said. 'They have driven sterling up too high and put up taxes too much. " http://www.guardian.co.uk/business/1999/feb/24/4

As a whole, though, the sentence "but we find your goods too dear" sounds odd to me for a business context. "But" sounds too crude (I'd go along with hm's "Unfortunately") and today contrasts oddly with "we find your (noun) too (adjective)", which is more old-fashioned/literary.