Keeping the house

My parents are coming over from Europe this weekend. It will be my father's first time in New York, ever.
So I decided to get some help. A housekeeper, since neither M. nor I enjoy cleaning. I do it only when I really, really have to. M. only does the dishes. We do the laundry together.
I called one whose card I found in our laundry room. She said she charges $80 for two bedroom, two bathroom apartment. I thought that was very reasonable.
This morning she shows up on time, with another young woman. O.K., I guess, two is better than one.
They were very young, much younger than housekeepers I've seen before were. Late 20s, maybe 30. And they looked nice, you know, nicely dressed and wearing makeup.
They spoke Portuguese between themselves. I didn't ask them where they're from. Brazil?
They did a very good job. There was a lot of work, I must admit. Dust bunnies every where, for one. So, I'm giving them a check and a tip, and one of them asked me:
"So, would you like to schedule cleaning for every week? Or biweekly?"
"Well, I'm not going to be in New York for a while, so maybe when I come back...
I was thinking more of maybe once a month?"
"Well, then it would be $120, if it's once a month, you know, 'cause there's more work to be done. If it's biweekly you can keep your current price..."
I said I'll think about it. $120 seems a bit pricey. But I don't know if I want our place cleaned every two weeks either. Is there such a thing as too clean? It's just seems like an unnecessary luxury.
My lungs should be grateful for our guests:)