You may not be conscious of it, but you're diminishing the value of the product based on the fact that it's on a CD rather than prints...and you expect the client to feel the same way.
Well, you're right--they won't want to spend anywhere near as much on a CD of 45 images as they would for, say, 45 8x10 prints. In fact, they would not have even asked for 45 8x10 prints without already realizing that it would be expensive.
But from your business point of view, editing 45 images (to whatever extent you edit your images) represents 100% of the same labor up to the point that you either burn a disk or upload images to a lab...and that represents 90% of the total cost of sales to you.
Those aren't arbitrary numbers--in my business, I would still have to charge for a CD of images 90% of what I'd charge to deliver 8x10 prints of those same images in order to put the same amount of money into my personal checking account. Even more easily than I can burn and package a disc, I can upload images to my lab and have a box of prints drop-shipped to the client...the only difference in cost is the printing, and that's only another 10% of the total.
The problem: People don't value CDs for personal commission work, regardless of the images on them (it's not the same circumstance for commercial work--that's a wholly different ballgame). People expect to spend maybe only 10-20% for a CD of what they'd expect to spend for an equal number of 8x10 prints (and let's not forget that a CD of high-res images can produce much better than an 8x10).
That's the main thing that sucks about selling digital images without a mandatory print package.