Growing pains depend on conditions as well. I started out on keggles and a 72 qt cooler, five and six gallon carboys. Now I have 16 gallon spiedels, just picked up a 130 qt cooler and am looking to go to 25 gal pots, in just a little over a year. I also am keeping a smaller set to play around with experiments and doing small batches inside for test batches. Now am gearing up to build a new brewstand and searching for an upright freezer.
So even if you think it is enough, do yourself a favor and think out the long term in detail. If you want five gallon batches to keg, is you pot big enough to hold the grain for really making a 6.5 plus batch with correct water ratios? It's a lot of little questions you need to look at when deciding what size is worth it.