How can you price attribute options in drupal commerce properly? Currently I am creating a site for a repair shop. Say I am repairing a laptop motherboard:

Motherboard Repair = $100

As with a motherboard repair, it could consist of a power slot repair, cpu replacement, memory replacement, or video card replacement. I charge $100 for any of those repairs, but I consider them as a Motherboard repair. I want to create a page where they can select one of those, but not create a SKU for it. How can this be done? 

In Ubercart, it would just be 1 product and 1 attribute with those 4 options. Since they aren't tangible products they don't need an SKU. Its more of a reference for the business owner to know what to repair which is selected by the customer on checkout.

Now say if I did have varying prices for each of those options. How can that be done too?
As per your requirement you want to give option to the user to select one from many option from your given list while purchasing the product, but you don't want to create separate SKU for each of them. I think Commerce Option module will work for you in this case...I hope it help...Good Luck :)