A 6.5-284 will eat a barrel in about 1200 rounds. Now, you have a couple options here. If you hang a whippy spaghetti barrel on it chambered in this cartridge then your going to have to replace the entire barrel. The more affordable option is to get yourself a heavy contour varmint barrel with a 3" long cylinder. Order the barrel to finish at 30" or 32" and then when the throat gets shot out, take it back to gunsmith guy and have it set back enough to chase out the throat with the same reamer.
Walla, now you have a brand new barrel all over again and it's only 2-3 inches shorter than it was. It'll still hammer out to a 1000 just fine until you drop down below 28". That seems to be about the shortest you ever see on a target rig.
Setting the barrel back is what this process is called. It's been done for years and it works great. Competitive shooters do it often. So, think of this cartridge now with a 2400 round barrel service life. Setting the barrel back is also not overly expensive in terms of gunsmithing. Just push the shoulder forward, trim some off the breech, pick up the existing thread and carry it to the new shoulder, and then get busy with the reamer until the barrel headspaces again.
There's a little more to it, but that's the meat of the process.
Done properly the only thing you'll notice is a slight reduction in overall weight and your bullets dropping off a touch in muzzle velocity. It'll shoot just fine. Stoke the load with an extra bit of powder and your back in business. That's why I suggested 55 grains of 4831SC. It's not the fastest load, but it gets the job done and gives room to grow.
to directly answer your question about alternative cartridges, just consider this: What your going to find very quickly is that whenever you decide to make a bullet go faster its going to cost you more money. Speed means heat and it means pressure, neither of which are conjunctive with long barrel life. Another thing to consider is how often you are shooting this thing. If your out every day or several times a week that is one thing. If you make it out a few times a month or a few times a season that is another. Be realistic with yourself as to how much money/time you can truly invest in this. If you are shooting it every day or several times a week then cost really shouldn't be a concern cause you've obviously got the disposable income to buy the components and a job/family that tolerates long hours in the loading room.
(This would be a big reason why I hang onto the one I have for dear life cause she's awesome and we have a 10 year old daughter who is infatuated with guns and bullets; makes for great child/slave labor!)
My point is 1200 rounds can last a lot longer than you think, especially in a hunting rifle.
If you'd like to talk more about it, PM me and we'll see what we come up with.
Chad