For a second, I was thinking there might be a downside to that for keeping direct benefits, but as I think about it, 3x50 may well be the way to go.
The situation I was thinking about is if they raise the minimum required for direct points. So, you buy 3x50 now, you get direct benefits. 5 years pass, they raise the minimum to 200 points - I don't think you would lose direct benefits as long as you kept those original 3x50 points as originally titled, right? But, if you sell 1x50, then you'd presumably lose direct benefits (regardless of whether they raised the minimum) and then need to buy whatever is required to get to whatever the minimum is at that point.
If you thought you might ever pass the contract on to someone else gratuitously, then I think keeping it at 150 (or whatever the minimum is) potentially becomes important because that entire contract would be grandfathered for the beneficiary. Whereas, passing on 3x50 contracts on to an heir, if the new minimum is 200, wouldn't cut it.
I think I have that right, but anyone feel free to correct me if I'm wrong.