Nothing wrong in starting small...while small bucks grow small weed, small in more than none. I was gifted my first light and had to be convinced to buy anything different ..... being retired, I squeezed my $ too. I bought the cheapest blurple I could find....$50 bucks for '600w' (100w draw) .... that cheap shit grew weed well enough that I began saving for more upgrades.
IOW....just do it.