Not me, but I've seen it best expressed in some websites. They'll advertise "rooms for rent from $x-$y/week plus $25 deposit/all bills included/furnished/$10 application fee", and then the specific room will fall in that range. So there's no guarantee that you'll get in at the low end, but you have an idea that you won't pay more than the high end, and how far under the high end you get is a perk.
Other times, it's a more vague "starting at $100/week" with no ceiling.
Looking at some of the most useful websites, I'm guessing they have zero vacancies right now, because normally, there are pages that illustrate which specific rooms are available at which specific address.
So--- just going from my notes, the blurb might start---
Rooms for rent starting at $400 monthly. A security deposit of $300 is needed before moving in.
Single bed $400 monthly
Twin singles $450 monthly
Two twin beds $450 monthly
Extra large room available for $460 monthly
Or you might have something like---
The Standard Room
$100 (crossed out) $90 (on sale)
1 bedroom with solid wood bed frame, full size spring mattress, chest of drawers for clothes and belongings, closet rod and mirror. Share kitchens and restrooms.
Select all that apply
() A/c window unit per week (+$10)
() Room rent for 1 week (+$100)
() Background check (+$10)
() Move-in fee (+$25)
() Room rent for 1 month (+$400)
() Room with Central A/C (+$300)
I'm a little less fond of the menu a la carte system, but I'm sure it works well for people who like to pay for things on their phones. I do like the shot of the exterior, paired with the shot of the individual room, especially when a biz has multiple rooming houses that all use the same website. --137.118.xx.xxx