Yeah, the problem with lightbulbs is buying them for pearls is inefficient (it eats almost an entire weeks railway dividends assume you're starting from scratch) and unless you happen to have a bunch sitting around you're not likely to regularly be doing a loop which rewards them. My suspicion is that buying beeswax at the rat market and then upconverting to memories is the best option unless we either get a more convenient source for anticandles or lightbulbs.