I have a two-month old mastiff-sized crate for sale. $60. If you go to Chewy.com, you will see it as the Frisco crate with two doors and three locks. It was $99 new. It is in perfect working order except for a couple of lower slightly bent bars where a very strong dog tried to escape. I also have a brand new green crate bed "unchewable" from K9Solutions. It was sent to replace one that was guaranteed to be unchewable. (My dog died before he had a chance to chew the new one.). It fits perfectly in the crate. I'm asking $60 for the crate bed.
I also have a used adjustable dog wheelchair from Walkin' Wheels. It is meant for a large dog. My lab was about 65 pounds and very long and there was plenty of room available had he been bigger. He LOVED it. I paid $250 for it used but I'm asking $150.