Those are from the MCM sale & I believe AG will not warranty them. The hospital might not fix them if something goes wrong.
The hospital will still fix dolls with an x just like any others. When you send a doll to the hospital you are paying for the service and they have no probelsm taking your money - or mine at least.

The x is very tiny and is placed in the corner of the rear seams where they come together - not at all noticeable unless you are specifically looking for it. It is placed there to prevent returns to AG for full retail price, not for doll hospital reference should she arrive with an "ouch-ie" accompanied by repair form and payment years later.
If the doll is for play, it should be fine. We have some dolls from the MCM sale (with the X's) and they are great. Any flaws are very minimal and some of the dolls, I can't even see what might have been wrong with them.
Keep in mind when bidding though, many people got the Just Like You Dolls from the MCM sale this month for $25. Over the summer they were $35 I believe. Don't pay a huge markup if you can avoid it!
Over the summer, dolls started Saturday morning at $55-$65 plus WI sales tax - not a mega savings or a huge profit potential if resold when purchased at that price. Mia was at full catalog price, as were all her accessories. Only limited dolls - those nobody bought the first time - were reduced to $35 later on.
I just came from last week's sale. The mob mentality was absolutely horrible. MCM was not prepared for the madhouse it quickly became and completely under-estimated the turnout. Lines were hours long, both for entry and for checkout. There were no porta-pots brought in like they do for the July sale and in the morning those waiting in line were not allowed to use the warehouse restroom. Thankfully that changed later in the day, but at 11 am DD8 and I were told to "go find a bush". When the doors opened we were crushed against the tables, pushed, shoved, and, several times, trapped. A grown man grabbed two clothing boxes right out of DD8's hands.
Having witnessed the craziness of last week's sale, anybody who successfully fought thru that crazed crowd and poor conditions for a full day (and it did take all day) just to resell for a few dollars deserves some profit IMO. No way would I do it. Heck, I was so anxious to get out of there after several hours that I even forgot to buy a few things DD8 had on her list.
I get a kick out of the holier-than-thou members of an AG message board who will criticize ebay/craigslist sellers for making $10 but hire "personal shoppers" and pay them $50 "for their time & gas" to buy sale items for them while they sit at home. I spoke with one lady from Chicago while waiting in line who said she made over $400 just shopping for board members. She'd listed on ebay in the past but won't now after discovering that "shopping" pays so much better with no need to put up her own money first. And to think, I do that free for family & friends every year. You know, even though we enjoy the trip, my time is pretty valuable too - wonder how they'd feel if I started billing them...
