On Spell Components

So I've been seeing a lot of stuff about the use of spell components and whether or not they play a big part in the game. There seem to be a few basic opinions on this issue.

1. This group prefers to assume that a magic user has whatever they need to cast their spells, UNLESS the component in question either has a monetary cost or is extraordinarily rare/magical in nature, such as the components for the spell Repulsion:

The material component of this spell is a pair of small magnetized iron bars attached to two small canine statuettes, one ivory and one ebony. (PHB pg. 86)

In the case of some spells (generally those that are either very high level or a necessary part of the adventure) a small quest or some form of sacrifice or difficulty is presented, effectively treating the spell in question as a reward of sorts.

2. This group believes that spell components should be treated as ammunition - if the magic user doe snot take the time to at the very least visit an apothecary or go foraging then he has no way of replenishing his stock. In this case components are logged and tracked much in the same way that projectile ammunition or potions are. This is seen as a way to keep the powers of magic users in check by limiting their ability to spew powerful spells that require fairly simple components (Fireball, for instance).

3. This group thinks that spell components are extras - and therefore not necessary to the casting of spells. However, if a player takes the time to gather the listed components, they can be used at the time of casting to amplify or extend the effects of the spell in some fashion. The components are still used up in the casting, but this allows a magic user to keep a reserve of components for when his spells need that extra boost.

I'm a fan of the easy route, or opinion 1. It is generally assumed in my campaigns that the magic users have a catch-all bag of components that they can draw from, and I still have them go the extra mile to find, buy, or otherwise obtain components that are bizarre or rare. I've considered other methods of dealing with spell components, but the players seem to be okay with what we have agreed on and I see no reason to change it yet. Maybe in another campaign.