We also will have to replace the carpets (the sons room is COVERED in stains), and it's going to be pretty pricey.  

But you need to get it on the stains to work so you'll have to peel back carpet/pad to get to the sub-floor stains.

It  doesn't have to be refinished, it looks pricier than carpet and is more durable, and shouldn't stain.  

The move in inspection then becomes a simple matter of identifying items where repair or replacement did not make sense; in another thread hardwood flooring had stains, so replacement will be costly and in that case the move in notes the condition so that tenant understands that this will not ding the security deposit. 

They even work with us where, for example, on one turnover last year we came in town and did what we wanted (pressure washed house, painted outdoor trim, stained decks, fixed fence, etc.), then they finished it up when we were done.  

@Linda S.Sometimes you read these chains of responses where each poster is obvious just trying to be holier than the last one...usually when it's a landlord asking about how to stick it to a tenant over something like a stained carpet or a ding in a door.

Let's see here....1) A few weeks prior to tenant move-out I send them a cleaning checklist as well as the two pages they signed listing damage and cleaning fees2) I use the same paint colors in all my properties.3) My Clean Magic Erasers are amazing and will remove wall scuffs and random stains. 4) When buying larger items I utilize the Lowe's 10% off trick (spending .99 on eBay to buy a Lowe's 10% off digital coupon and using the code online or in store - this hack has literally saved me thousands).5) At my multi-family properties I include various items near my coin-op washer and dryer: a laundry  table for folding, a roll of paper towels and a bottle of cleaner so the machines can be wiped off; I also include some laundry-related items such as stain remover, starch spray, etc (I buy it from Dollar Tree and it lasts a while - I think the tenants appreciate the gesture). 6) At the Dollar Tree they have a toilet cleaning gel product called Lime-A-Way.

I closed on a house earlier this year and it was filthy, plus had major stains all over the carpet.

Half the time people compare the newly renovated property down the road with their apartment that has old appliances, stained carpet and needs a paint job.

There is certainly a stain in that picture, but the photo itself does not appear to reflect mold.