How often to groom depends on the rabbit breed, long haired require more grooming than short, etc. Powder is constantly shedding, so I brush him every couple of days and pet the hair off him daily (just kind of pluck the loose patches and run my hand over him to remove the loose stuff).
For cheap barriers try NIC grids. I have a couple of things I use besides baby gates – I have a plastic “door” to a kids toy crate that is tall and I arranged so the doors can’t be opened, which works great since they can’t jump over it. Just throw a weight against it and they can’t push it either. Get creative. Anything they can’t chew, can’t jump and is solid works across doors even if it doesn’t look pretty. I also have baby gate _panels_ instead of full baby gates, so I can take them apart and put together whatever I want, they click together and pull apart really easily… I got them free, but they are about $60 at BB&B and they are enough to block off the living room, bedroom, laundry room and have some left over. If you check craigs list, often you can get baby gates, NIC grids, etc really cheap.
If she eats her litterbox, you could make one yourself out of a sturdier material. Any container works. Try to get something not porous though, since you really don’t want the pee seeping into the material and smelling up the place.
For veggies… get the cheap stuff. Cilantro at my store is $0.88 a bunch and the buns love it, parsley is cheap too, etc. You can also start a little indoor garden with wheat grass and herbs on a windowsill… saves a lot of money that way!