Izmailovo can be endless fun to scavenge through, but Sasha advises a game plan!
First, remember that the complex is divided into distinct zones – artifacts of the Soviet era and beyond are found on the upper tier, with the souvenir section down below at street level. If you're searching for one of those vintage clocks, for instance, knowing where to start will much better keep discouragement at bay (a lesson I learned the hard way the time I couldn't seem to escape the wooden dolls of political figures all pregnant with each other).
Tip two: if you want to collect like a museum curator, keep an eye out for certain historical themes, especially state-organized events. Authentic space race and Olympic Games memorabilia are classics that, when in good condition, can make for some pretty special collectors' pieces.
Also, to bolster your bargaining power and better communicate with the sellers, who are mainly accustomed to Russian consumers, come armed with a native Russian speaker if you yourself aren't one.
Finally, the selection and pure scope of the place easily overwhelm, so setting budgetary constraints may help you keep your head. Sasha always makes sure to bring a set amount of cash when she visits (and it's cash, not cards, you'll need here), to make sure she doesn't get carried away.