You can try a large (or bigger) wire dog crate. They are a good size for a rabbit. You can add a level if you want as well. You might be able to find a used one in good condition for less than a new one.
An x-pen can also be suitable. You will need a bottom of some kind and it needs to be tall enough so your rabbit can't jump out (or put a top on).
NIC cages are also good, but take some work to put together. You can find the grids at stores like Canadian Tire, London Drugs, Home Depot, and Walmart. You then need zip ties to hold them together and a floor.
Most store bought cages are too small for an adult rabbit. There are some out there that are 2X4ft which is a good size but they tend to be expensive. If there are locally owner pet stores, they might be able to order one for you at a better price than a big store.