Tier 1 runes are fine. They are so inexpensive in IP that you can buy a full set of armor seals, MR glyph, and AD/Mpen marks plus AD/AP quint and wind up not even spending as much as a single champion from the past 2 years.
Skip tier 2 runes, they are significantly more expensive and the marginal utility isn't worth the cost (edit: I'm reading riot reduced their cost, if this is true you can consider them).
Once you hit level 20 (maybe a bit sooner), start buying tier 3 runes with your IP and don't spend it on anything else. You'll hit 30 with tier 3 armor seal/MR glyph/2 sets of marks/2 sets of quint. From there you can build champion pool or pick up more diversified runes.
But what to do for now? Pick junglers with better sustain. Nunu, fiddlesticks, warwick are examples of inexpensive champions who can jungle with minimal-to-no rune investment even now. Amumu is a great jungler too and inexpensive but rough without runes.