Why choose? A standing order of 125Tcredits now comes with a minimum of 2 new PSA per month, Just bid fifty times in an auction and you earn a PSA. Bid 100 times to earn two referrals and save the other 25Tcredits to for next month so you can buy 3 PSA that month.
The other option is t try to win more Tcredits with your bids making your potential windfall dozens of new PSA per month.