Actually, I'm planning on more complicated spreads than simple credit or debit, and the main "work" of my strategy is based more in the choice of options than the nature of the spreads; it's a fundamentals-based speculation-based strategy, not day-trading. But yes, the low cost per contract is how I hope to make a substantial amount of money without starting with a lot.
Also, I'm not quite certain of my strategy yet (the theory seems sound, but I'm not certain that my ability to read the market will be as good as I think), so I'd rather not risk a substantial portion of my assets on it until it's a bit more tested. If it works as I hope, my investment should grow enough anyway.