I am not going to make some guarantee that you will make a lot of gold, or any for that matter, with this gold making tip. At least not like the one I gave when pet battle weres announced and I told people to keep all their extras and to sell them on other servers as a way to transfer gold between servers. This tip will not be that huge, but it is a tip just as much as any other.
With the new expansion coming we don't know exactly what to expect from the stat squish. All we know for a fact about it is that it is coming. How stats will be squished are still a mystery and that is where this tip for making gold comes from.
If you have the extra bag space to hold on to some of those raid level BoEs from older expansions, like the 264 ones that seem to drop like candy if you do an ICC run, hold on to them for a little bit. You can always disenchant them later, no harm no foul.
The idea is this. We do not know anything about the stat squish. Some of those BoEs that we take for granted and just disenchant can become best in slot for a twink. If you have ever sold twink gear before on the auction house you will know that it sometimes sells better than transmog gear. While a lot of those BoEs that drop from raids have little to no transmog value and that is why most people disenchant them they might turn out having some twink value.
Sure there are not as many twinks as their used to be but some 60, 70, 80 and 85 BoE gear can turn into the golden goose of the next expansion. Sure they will be easily farmed (if the ability to solo stays true as we have been told it will) but people will want things now. It is just human nature. So they might be willing to pay big gold to get it the second the stats change when they see how great it is for them instead of farming it for themselves later.
Like I said, I make no guarantee this will be a huge gold maker, for but the cost of a few bag slots to hold on to them just in case they do suddenly end up having a lot of value added to them after the squish might be worth it. Just like the extra giant sewer rats and other duplicate pets I had sitting in my bank for a long time sold for huge gold as soon as pet battles came out. Sometimes holding on to some things we think are worthless end up being wrong because when things change, like with the squish, value can come from a place you least expected. If it doesn't, you can always disenchant it later.