" However in saying that, our average wind that we have been sailing in these past few summers has been between 20- 25 knts with gusts to 30knts. This has become the norm these days."
Yikes, Where do you sail - the only area I can think of with such prevailing wind would the Roaring 40's, or perhaps better the Furious 50's. You sailing out of Cape Horn?
The extra work costs in an offshore sail relates more to durability, by providing extra protection for chafing and exposure, such as triple row stitching, heavier grommets and use of leather patchess. I think durability and strength are different characteristics - strength comes primarily from fabric weight. If you want sails for higher wind strengths, order heavier weight cloth. I would not buy Offshore quality sails for day and weekend sailing as you describe, unless cost is not an object. Consult your local sailmaker.