Because of the variety of area answering services, it's a good idea to shop around for the one designed to meet your special needs. Prices are basically competitive, but you may have to try several, veteran users warn, before you are satisfied.

A sampling of services:

* Basic service with personalized (your name or company) answering from 9 to 5, with a limit of 20 incoming calls a month, for $25. A good "insurance policy," as one company put it.

* If you're willing to share a line with two or three others, unlimited incoming calls five days a week for $30 a month. The phone will be answered with only the last four digits of the number assigned to you.

* Call forwarding, about $44 a month for basic business-hour service.

* Basic business-hour service, combined with lease of the silent beeper, about $70 a month, allowing 75 incoming calls.

* "Relay" calls, in which the service will call customers or friends and relay your messages. Either 50 cents a call or a flat $15 on top of the basic $37 monthly rate for dawn-to-midnight service seven days a week.

* For the ultimate in answering, one service will lease you a mobile phone for $121 a month, adding an "air-usage" monthly fee of $37. Tack on another $37.50 for their basic call-forwarding weekday service with a 50-call allowance and you're in business. Using the phone line, however, will cost an additional 35 cents a minute during peak hours, 25 cents a minute other times.

Remember when signing up with an answering service that there may be another piper to pay: your local phone company. If you go with the increasingly popular straight call forwarding, there will be an extra phone company charge of about an extra $2 a month.

If, however, you want a private line linked up from your home to the answering service, there will be a one-time installation charge in addition to a monthly mileage charge calculated on number of miles of telephone line.