Hello De,
Congratulations on your engagement and upcoming wedding. Let me try to answer your questions. The major factors which determine a photographer's fee are their skill level, labor involved, overhead costs and material costs. The more skilled the phtoographer, the more expensive they will be. Next, every event a photographer photographs, has overhead. That includes the gas, insurance, equipement depreciation costs, etc. These costs do not change from event to event. The last cost if for the materials provided. Since you are not getting an album, this is not a factor. BUT, the photographer still expects a specific profit from each event. So even though you are not getting an album, they are still adding in the profit from it.
Another thing you need to consider is that since you are asking for a disk of images, you are depriving the photographer of income from the sale of wedding images. So the smart photographer will determine the average reorder profits and the labor to create the disk to determine the value of the disk. Depending on the photographer, they may provide you images straight out of the camera or they may fully retouch each and every image. Every photographer is different. You will need to discuss this with your photographer to determine what they will be giving you.
Finally, there are two concepts, copyright and usage license which you should understand. The photographer owns the copyright the moment they take the photo. A copyright allows the owner to determine who, what, where, when and how many copies can be made. This is the most valuable of the rights available with a created work. A copyright owner may grant a usage license to somebody detailing the conditions underwhich they may make copies. This is a bit less valuable than a full copyright. If you want the copyrights, you could actually prevent the photographer from using their own work in their portfolio! I suspect that you really want a personal usage license to allow you to make as many copies as you want and create your own album.
So while you didn't think you would have to pay a lot for what you wanted, what you'd like does represent a lot of labor for the photographer. In addition, a photographer can only be in one place at a time. Shooting your wedding means they can't be a another wedding. Therefore, a minimum profit (determined by each photographer) will be required no matter what products are being delivered. Perhaps you should check out less experienced photographers who are not charging as much. However, I would be remiss if I didn't mention that there are risks associated with using a less experienced (and less expensive) photographer. Please feel free to contact me should you have any additional questions.
Howard Kier, Certified Professional Wedding Photographer
Magical Moments Photography