Separate out the concepts of cellaring wine and drinking wine in your head. I would only cellar wine that I’ve tasted, but I’m fairly liberal about buying wine to try now and see if I like their style. At this stage, if you look at the cellar and realize that you haven’t tried half the producers in the cellar, you’re probably doing it wrong. (That may be OK later on once you know a producer well, you may want to let their young vintages age while you drink the older ones.)
I would aim to grow your cellar slowly. If you’re at 150 and aiming for 1000, plan to add about 50 bottles a year at most. You’ll be at your goal within a decade, and you won’t have nearly as many duds as you would if you did that in 2-3 years.
And I would emphasize what others have mentioned: taste great wines that aren’t expensive. If you find that you love Prum, or Huet, or Loire Cabernet franc, you have saved yourself a lot of money. The flip side is true too: If you find that you really love Krug champagne or aged bordeaux over cheaper stuff, then buy one bottle of that over a case of cheaper wines that you’re not as passionate about. You’ll be happy later on when you have too much wine: quantity is everyone’s ultimate issue in wine, no one is worried that the wines in their cellar are too good.
Lastly, people are incredibly generous on the boards. Make friends from here that you can meet up with. Some people will open incredible wines that they bought when they were more affordable, and I would have never been able to try them otherwise.