My experience has been similar to Mia Sorella, over quite a few years of shows and 3 employers (current employment involves no shows, so not as relevant to your questions).
$450-600 per week. Some paid by the week, so Mondays worked blended in to that rate, but then we generally get a little time off still paid. Others paid by the day and if you don’t work, you don’t get paid.
Housing is either provided or paid for. Accommodations on the road are arranged and paid by employer.
Usually given some vehicle access when living on barn site or at a show, but may be shared with other staff. When living off site and having own vehicle, no compensation for gas (or the million other expenses having a car brings :(), but if you take your car on a long trip to a show (and especially to Florida!) that gas is comped. On a large staff it usually works out nicely that some people want their own car there, while others would rather not put the miles on, because the employer likely wouldn’t pay for everyone’s personal vehicle. In cases where people fly in or go with the horse shipper, rentals are sometimes done, again covered by the employer (and again, usually shared unless you have a super sweet boss).
Meals at home are your own responsibility. At shows it’s usually covered on some level, whether a casual “hey I’m going to the concession, want anything?”, having a tab with the food provider, or being handed $100 cash at the beginning of the week. The latter is typical at away shows, since we don’t tend to eat every dinner with the boss present [and if anyone out there is adding up whether $100 will cover 3 meals a day for a week, it won’t. Because even if we are staying somewhere with a kitchen, we’re probably too tired to use it. But it’s better than nothing]. The former works better at the local shows. There are always lots of random coffees and food treats from clients and employers, as well as plenty of nice dinners. Very little makes a groom happier than food 
