Right. The guidelines for whether an item was available were based on the cost of the item and the size of the community in which you were shopping...
5th level feat vs a 1st level feat, IIRC.
But the cost difference actually reflected that the potions were much easier to acquire. A potion of CLW was 50 gp, a wand of CLW 750 - so you had to be in a larger community to find wands for sale.
All fairly consistent, really.
Let's not forget too, the wizard got that Craft Wand feat as a bonus feat as well. So, you crafted scrolls (who bothered with potions?) for 4 levels, and then wands after that. 375 gp for 50 charges? IIRC, a 7th level PC's was expected to have 16 000 gp in character wealth. We're talking a minor, minor expense, not even a 5% expense if the PC's were buying the wands at retail, just about 2% if they were crafting them. You got a wand for everyone and off you went.
It was very, very easy to do an end run around the Vancian limitations in 3e. Never minding later feats that gave you at-will spells, but, simply a couple of crafting feats and you were off to the races. You didn't put your combat spells in scrolls and wands - you put all that utility stuff there. Stuff that you weren't going to need all the time, but, so handy to have when you did. Water Breathing, Knock, Message, all that kind of stuff.
IIRC, a wizard could have about 8 scrolls of every level he could cast for about 10% of his character wealth. So a 2nd level wizard has 8 1st level scrolls, a 10th level wizard has 8 1st, 2nd, 3rd, 4th and 5th level scrolls. More than enough to get you through to the next level where you simply replaced whatever you used and move on. Blast away to your heart's content because you effectively can never really run out. You'll run out of bad guys long before you run out of spells.
And these things had just such a massive campaign shifting effect. I tried to run a naval based campaign - the PC's were merchant/pirates. Cool. The wizard player took two minutes to realise that an Extended Wand of Fireballs has a range far longer than any siege weapon and is ten times more effective. Combined with a Lyre of Building (making a structure immune to all damage for an hour) and a fairly minor expenditure of cash from the group's pooled money and they were basically immune to all incoming damage and had long range artillery. So, I had to start adding the same thing to all the enemies. Or trying to work around it constantly. Complete game changer. Two items, neither one was out of line for a 7th level party.
3e was brutal for this sort of thing.