At the corner nail salon, you run the risk of getting sloppy work. High-end spas are expensive and frequently booked. But Greenwich Village’s Beauty Jewel (146 W. 4th St., at Sixth Ave.; 212-505-0600), which opened in June, threads the needle. There’s pampering without pretension, and it can accommodate lunch-hour pit stops. On a typical afternoon, decked-out ladies of leisure are getting Jewel Glow Yon-Ka facials (one hour for $90) or relaxation massages (also one hour for $90) while frazzled NYU students duck in for a well-priced manicure ($12) . Wealthy beauty zealots can invest $200 in an annual membership that gives 20 percent off all treatments every visit, and cash-strapped students can enroll in the free discount program for a 10 percent markdown of their own.