There is no "usual". Every deal is different. Some sites do not cap travel. Some cap it at 500, 400, ... etc. Some pay travel in but not out. If you have a question about a particular job, call the recruiter and ask. Better still, try to get the answer by email so you will have it in writing when they try to change the story later.
If you got to the site and then found out that you were not getting travel pay home, it wouldn't be the first time.