It is best to work out a yearly schedule for these extra charges before you bring your horse. You won't be surprised and you can budget as needed. Don't assume your horse is being taken care of properly. Your research at the horse shows showed you that your trainer treated clients and their horses, or spouses and children very well. Don't assume they will treat you and your horse just as well.
Assumptions can be too costly.
You need to observe everything your trainer does with your horse and evaluate your trainer carefully. Have you been in horses long enough or do you need to go to the library or purchase your own books in order to understand what you are seeing in the show ring or at the stable. Spend time reading and asking informed questions. Show up unannounced and observe once that your horse's stall is clean, that there is enough hay and grain present, or that your horse is being worked consistently. Find out when the schedule is for working your horse next and be present to observe but don't demand a command performance.