Crates can be SO expensive, especially the size we need for big dogs so I get mine on Ebay. For my last dog I got a GoGo crate off a pet supply place there and it was awesome. I would recommend the wire, suitcase folding style ones. They just fold up in a snap, no assembling, and fold down just as easy. For these pups I couldn't find the size I needed from the same company on there so I went with a value crate, same style and everything in a size: 48"L x 30"W x 35"H. Supposed to be for pets up to 110lbs..larges t I could find so I went with that and it's plenty big. It's a very nice crate, works perfect for them. Except I need to get another because they are finally outgrowing sharing one. Anyway I got that last one for like $76 including shipping, which is a steal compared to most places so I was happy.
Oh and I forgot to mention, it did come with the tray and also a divider. Since it will take him awhile to fill out a crate of that size, you may want to use one. If the crate is too large, they have a tendency to potty on one side and sleep on the other, so smaller is better and then take out or move the divider as he grows. Because I have 2 in there, I never needed to use it but it comes in handy.