Hot, your
lamps should not be failing at those low hours. You need to ask SunCapsule for some help with your booth. You might be helped by installing the electronic starters if you haven't already done so. They should help with lamp life extension. They are discussed in other threads here. Your power coming into your booth must be too high. Are you boosting it? It does not need to be above 240VAC. SunCapsule has been willing to work with me in the past when I had pre-mature lamp failures. Talk with them.
Also you ought to give consideration to their lamp rotation schedule, so the cost isn't so great at one time. It's quite effective, and levelizes your lamp expense.