The high cost of higher education is putting the squeeze on seminaries, where the tab for studying for the priesthood surged past $10,000 last year, a study by a Catholic research group shows. The study conducted by the Center for Applied Research in the Apostolate says double-digit inflation could push that figure above $17,000 a year by 1983. A national task force of clerical and business leaders called for some hard-nosed actions by schools, dioceses and religious orders to improve the fiscal management of the nation's 54 Roman Catholic seminaries. The task force recommended that no new seminaries be opened; that those operating below 50 percent of capacity "consider merging or closing," and that dioceses consider regional planning. The church already has seen a severe winnowing of theology schools as the ranks of seminarians thinned in the years since Vatican Council II. From a peak of 8,916 seminarians in 133 theology schools in 1966, enrollment fell to 4,327 in the 54 surviving schools last year. Those seminaries operated at 46 percent of capacity in recent years, the study estimated. While enrollment of prospective priests fell, most schools registered sharp gains in enrollment of nonseminarians in theology courses, it found. The average cost of training a seminarian last year was estimated at $10,081, including $5,161 for the academic program, $2,194 for "spiritual formation" and $2,726 for room and board. The study noted that the $5,161 for theology studies compares with $4,252 to train a graduate student in English, $8,788 in mathematics and $11,480 in chemistry in 1978-79, according to figures from the Council of Graduate Schools in the United States.