Moneylender, Silver, 3 Estates.
Unless your opponent drew a Militia or something turn 3, seems okay enough. Guaranteed $5 turn 4, even if you don't get to use the Moneylender that deck cycle.
That isn't okay enough, that's awful. It's the equivalent of getting a Golden Sombrero except your turn 5 hand has two Coppers instead of two good cards. While you bought only one $5 t3-4, your opponent probably bought a $5 and a $3-4 (or even another $5 if they were lucky) and trashed a Copper, which puts you at least one turn behind if not more.
Golden Sombrero doesn't guarantee you get a $5 though. It's only a 1/6 chance of it I believe. This still seems better than that, honestly - I'd probably rather have the guaranteed $5 and draw my ML/S on turn 5+. I think I overestimated the chance of not getting a $5 hand in my head T3/4 with a Moneylender/Silver opening, now I think that through slightly more it seems fairly rare. Asides from drawing both S/M turn 5, and the situation above you can also draw one of them turn 5 and draw MCCEE/CCCCE or SCCEE/CCCCE turns 3/4 - I think those are the only situations that don't involve getting attacked or involve other things that modify hands. So yeah, it's pretty bad overall.
That said I'm not sure how much it puts you behind. Obviously compared to the ideal scenario of drawing them turns 4/5 and getting $5 both times (or potentially even $5/$6), while trashing a copper it's a lot worse. That's a somewhat uncommon situation though I think. More often you'll be down a copper and/or up a $3/$4 card, which isn't good but it's also not totally awful.