Buy them. Really lesser runes are so cheap and give only a small chunk less of the stats. I think lesser runes serve as a nice boost for little cost to points. They work well to fit in until you can get Tier 3 runes. Until then I just suggest getting tier 1 to fill in the gaps and then as you get more IP you can then buy tier 3 runes to replace tier 1. Don't bother with tier 2. They cost a decent amount compared to tier 1 and aren't worth it.

A few lesser runes should help you a bit. Quintessance I would recommend at lvl 10 just because it gives a higher bonus.
I personally have like 3 lesser runes and I'm saving IP for level 20 to mass buy. Hopefully a noticeable difference.

Hiya, buy the lesser runes. Once you get to 20, you would have enough points for higher tier 3 runes and that's what you should get. Tier 2 will be a waste.

Although, if you plan to have 2 separate/different runebooks, what I did before was have 2 Tier 2 pages (it was nice), but then I just found myself wanting to upgrade them to Tier 3. So yeah. Sooner or later, you'd want the strongest runes.

Yeah, lesser runes are dirt cheap. Get them.

If you want to have some fun with them, buy massive quantities of the cheapest possible runes and combine them up. You need to be 10 or 20 to buy higher tiers of runes, but if you combine to them, you can start using them immediately. Hang onto the inevitable flood of useless tier 2 runes, and combine those to get tier 3s, which you can then pair off if they continue to suck.

I wouldn't bother. The R1 runes are cheep, but they still cost something. You'll want a T3 book eventually anyway, so why waste money on T1? Level 20 is not that hard to get, and by the time you should have an idea of what champions you like to play, and what runes might be useful.