I don't think anyone has suggested this, so I am going to.
One way for those residents who don't wish to run in-world businesses to get more $L without hassle might be an $L subscription service.
Once a month there is an automatic charge to their credit card for a pre-determined amount, let's say $10. They receive in-world how ever much $L that $10 buys at that day's market rate. A re-occuring automatic buy order in other words. Spread it out through the month to keep odd spikes down. The $L would have to be purchased out of the market, obviously.