Look into getting Lucy outfits for her maid and personas.

"So Lucy... Would you consider getting a maid outfit, or a belly dancer one?" Natsu asked.

Lucy blushed at this. "Um, well Master, I'd love to, but they are expensive pieces of clothing, and I have to keep up with my rent..." she replied, looking a bit ashamed. "I mean... If you want, I will do it anyway..."

"No, no, I'm not going to have you homeless," Natsu denied. He then turned to Virgo. "I don't suppose you could give Lucy a maid outfit?"

"Apologies Master," Virgo inclined her head. "But my maid outfit is part of my being, so to speak. I can shed it and even loan it out, but it always returns to me when I return to the Celestial Spirit World. And of course, there is only one I have, so if you desired to see us both in a proper attire to serve you, you or Princess Lucy will have to acquire a physical outfit for her."

"I see... That's a shame," Natsu grumbled.

"I'm sorry Master," Lucy hung her head.

"Don't be. Not your fault things cost money..." Natsu replied. "...are they really that expensive? I mean, they're just clothes, and with how skimpy they are, I doubt there's much value in the fabric..."

"Unfortunately yes Master... belly dancer outfits are made of pricy silks, and a bit difficult to make for the average person, and maid outfits are also on the tricky side... The maid outfit would probably be cheaper though. Plus, well, sex sells, so of course fetish based clothing is pricy."

"Figures," Natsu sighed, crossing his arms as he thought to try to figure out an idea.