I can't say that I've played OSRIC-style in a LONG time, but from my memories of the game, it is much less dependent on the PCs having "the right amount" of magic and money.
As far as money goes, they should have enough to buy the mundane equipment they could need - decent non-magical arms and armor, a mule, all the camp and dungeoneering gear they might want... but not a lot extra. If they were playing in a campaign, they'd be saving to pay for training. In a one-shot they're not motivated to do that, so you want to keep them to pocket-change.
As far as magic goes, I'd give them each a small, expendable item or two; a potion of healing and something else, a scroll and a potion, or a single-use alchemical item or something similar. And then there should be 1 magic weapon or so, and maybe ONE other permanent magic item in the party. I'm presuming this is a party of 4-6 PCs. I'd say by 3rd level they will have acquired one permanent magic item per 2 PCs. If you feel this is unfair to the PCs who don't have a permanent item, feel free to give them an extra expendable item. Just keep all the items low powered. +1 weapon, wand of 1st level spell, or something similar.
That's how I remember the game, anyway!