I wouldn't put much thought into it until you're level 10 (Access to T2/T2.5 runes), just play as many characters as you can and purchase those you enjoy for now.

Before you buy anything with your IP, check 2 things:

1. The cost of T3 Runes.
2. You can't buy Runes with anything except IP.

For those with enough patience, don't spend any IP on any runes until 20, then start building your first T3 set. Don't spend any IP unlocking characters, as you should take advantage of your noobness by playing every free character available on every rotation swap. That gives you the knowledge you need to determine whether you want to buy either of the bundles, or just a few select heroes with RP.

Just don't spend all your IP on T2 Runes and 3-4 1250 IP heroes, as that's another 6-7 T3 Runes or 2 more T3 Quints.

I'd say if you figure out what your fav 2 450 IP heroes are and know you aren't picking the wrong runes, you could get about 50% of the effectiveness out of T1 runes for a fraction of the cost, but if you buy ones that you figure out are useless later, you're stuck with them or betting on luck with the combiner.