Probably 1-4 crickets, not very many at all as cricket keepers are a waste of money entirely. They dont provide enough room for them, which often causes smell, quick deaths, and you having to go out and get crickets more than usual.
A proper "cricket keeper" would be a 60 or 90 quart tub with screen on the top of the lid. This would give them enough ventilation to not smell, and there would be fewer deaths because of the space. You could hold up to 2,000 or so crickets in this which would last you a month or more depending on the age of your beardie. 1-4 month olds eating around 30-60 bugs each day, 4-12 months old eating around 20-40 bugs a day or more, 12-20 months eating 15-20 bugs on a daily basis, and 20+ months eating 15-20 crickets every other day.