If you get it done professionally, it costs about $10-20 for manicure, $12-25 for pedicure and you get hand and foot massages to go along with it (returns from a cataclismic orgasmic flashback) hopefully from a HB.
At the place I get my haircut, you can go tanning, get a manicure, pedicure and obviously your hair done, all in one sitting if you have 3 hours to spend styling.
Are manicures worth it? Absolutely. They also provide for a very seductive tool in the bedroom as you can rub your nails along a womans skin without scratching them.
Are pedicures worth it? Here I must digress and admit i've never gotten one professionally. Clipping your toenails is a must and filing them down is simply common sense unless you want to slice into somebody in a jacuzzi on accident. Just use your best judgement and live within your price range.