EJ,
One thing I didn't see mentioned in the thread was a caution about split necks. I've done and for the same reasons. Money. If I were to do it again, the first thing I'd do is to insure all the necks were clean on the inside. I'd get two tapered expander buttons. One to go to .284 and the second to go to .308, and do it in two steps to minimize the splitting of necks. Then trim the necks. But before I did any of it, I'd check the headspacing of the .270 cases to insure they weren't too short for the '06 chamber. One way that has worked for me is to superglue a peice of printer paper to the head of the case and then trim it to the case head. If the bolt will close with one piece on it that's ok. If it closes with two pieces on it, that's no good.If you still want to use the .270 brass, get a tapered expander button the next size larger than .308 and expand the necks to the larger diameter and then size it back to tha standard .308 diameter. Just don't size the neck all the way to the junction of the neck and shoulder. This will give you a ring around the neck at the shoulder. Use this ring as a false shoulder and headspace the case so the bolt will close with a little effort. The first time you fire it it will form to the '06 chamber.
This works, I've done it. Its a lot of work, and if you have to get three expander buttons, it does cost a little money. But it's a lot cheaper than 250 cases. Buying new cases elemenates the problems and your cases have the right headstamp.

I've converted a lot of 6.5x55 Mauser cases to 7.5x54 French, and .284 Winchester to 7.5 Swiss. The 6.5 goes from .264 to .308, and the .284 goes from .284 to .308. Always do them in one pass over a n expander, and have never lost a case to split necks. Assuming the .270s are once fired, I would be surprised if they would split with that small a change. If they are getting tired, I would anneal them first.