I’ve finally gotten simulating ladder games for gems and exp working, so if you’re just shy of that piece of gear you need, go on over to a multiplayer ladder and hit the simulate tab, then start simulating. Or just leave a tab or two open on this link:
You earn 20x0.4 gems and exp from simulating, where x is the number of games simulated, so you can snag a few hundred gems pretty quickly, but it will slow down a bit as you simulate more and more games. If you eventually simulate millions of games (thanks!), you can get quite a few gems:
But the first few hundred come quickly:
Hope this helps!