Should I insist on a detailed quotation?
In a word 'Yes!'
You wouldn't buy a car without knowing all its features, nor should you entertain a quotation that doesn't spell out exactly what you are going to get for your money.
For example, you may be expecting 'double tracks' for your drapes and sheers. If this isn't detailed on the quotation and it only states 'drapes/sheers' then this could be misleading as your sheers could come mounted on a pole when you were expecting them to be track mounted on a double track with the drapes. Additionally, if the heading type is not specified then you may have thought you were getting an inverted pleat heading but actually receive a cheaper pinch pleated heading with your order.
'Swags and Tails' is another good example where what you saw in the brochure or in the showroom with trimmings is not what you receive. You may well receive swags but with completely different trimmings or with no trimming at all because it is not explicitly detailed in the quotation.
Given the cost of window treatments, there really is no place for inference on a quotation. You should insist that the quotation is fully detailed so you are assured you get what you are paying for.
DETAIL! DETAIL! DETAIL!