I think a service like this would be most useful for pre-load-development. If you hear of an interesting new bullet, it would be nice to get just a few, so you can load up a few mockups and check out things such as:
- what overall length is needed for contact with the lands
- where does this place the bullet's base, relative to the neck/shoulder junction; how does that fit with the powder(s) you might like to use?
- for a rifle with a magazine, how does it fit and how does it feed?
Once a bullet looks interesting, you could use your 12 bullets to verify that the bullet isn't a total dog in your rifle, and if it's 'so-far-so-good' you could order a few hundred with a fair degree of confidence...