Going strictly by OVR will sadly almost always get you into trouble. You need a plan. Then use players that fit that plan regardless of OVR.
Many golds are better than half of the diamonds for different strategies. There are also low diamonds worth more to your plan than high diamonds and several perfects. I started with a $50 investment. I open many packs because I like to. I have sold since PT started Perfect DeGrom and Sale cards when their prices were up because I think they suck in my scale. I bought players and cards each time. I sold a Perfect Lou Gehrig this morning because I got an Olerud(with defense even) that is very nice for my first base. I chose to turn the 100 OVR historical player into a pile of PP. I bought 2 diamonds and will buy 100 packs this afternoon with the remaining proceeds and have some left over. This is because I think OVR is vastly overrated and I have a plan and my own grading system that I stick to. Have I been lucky? Absolutely. But I dismissed OVR and used that luck
Good luck