No on the used carseat, you just never know how honest folks are. No on the crib as well. Play yards are iffy, but I would also say no on that. I don't know that there is much I would get second hand other than clothes, most often they have been barely worn as they grow so fast! I have clothes worn by all three of my boys that could still pass at new minus the tags.
I did by my bassinet used and it held up not only throughout my three boys but my cousin's baby in between.
Why not cribs and play yards?
id say no to the high chair too---i bought a used one and the height was adjustable and my son was sitting in it one day and it slammed down to the lowest setting---id stick with clothes--
Boy, I got all used stuff with my last child because he was a surprise baby and we had gotten rid of everything. I'd say as long as it's not that old and it's in good shape and you know that the brand is good and it's passed safety tests then it's ok. I got a used infant car seat that was barely used. I also got two used strollers that I still use and he's 3. I got a used high chair that was a real nice one and I used that until he refused to sit in it anymore. I got a used pack and play that looked barely used and was still fairly new. Now the cirb I got new! :) Only because my parents paid for that for me. I also got a real pretty bassinet from a consignment shop that he used the first 3 months. I think you can get some very nice things used if you just make sure it's in very good shape and check to make sure there's been no recalls on anything.
As fast as babies grow chances are the used things are barely used and almost new. Some of us just can't afford to buy all brand new things. Still, be careful and check everything out before getting anything used.
Things like strollers, high chairs, carseats, beds etc I would buy new unless you know where it is coming from. Especially carseats. You just don't know whether they were used properly or abuse by the previous owner so I wouldn't buy equiptment from a garage sale. I know that there is a huge problem on the westside of cincinnati with bed bugs and things like that so I am very leary about used things. Even clothes...unless they look decent and look clean I won't buy them and if I do i still make a point to wash them really well before putting them on the baby. Has she thought about a childrens consignment store. Here in Cincinnati we have a store called Once upon a child, and they are very trustworthy. They have decent prices and sometime they still have things in its original package or box like strollers and carseats and things. She might want to check that out.