The attitudes expressed in ''The Marketplace Menagerie'' {Business, Dec. 23} are the essence of what is wrong with the retail trade. Whatever happened to: ''The customer is always right''?

To whom am I to raise an objection? I am every member of reporter Kara Swisher's menagerie rolled into one. I am the Grinch shopper who prefers to pay 85 cents for a card instead of $4. Too bad if you've already rung it up; changing my mind is my prerogative. I am the Revolving Door Browser. Yes, I'm ''back again.'' You should consider yourselves lucky. I didn't have to come back.

I am a List Making Comparison Nut whenever I feel so inclined. If you don't want to offer me a competitive price, I'm sure I can find one elsewhere.

I am the Garbo Shopper who goes into a store to shop, not to establish relationships. If I want to talk to strangers, I'll go to a bar.

My wife and I are the Couple From Hell. Yes, you do have to please us both if you want the sale. If you find it easier to cater to singles, that's your business. Just remember, though, that you'll have to wave goodbye to the vast majority of disposable income controlled by two-career households.

If I was ever a ''Wrap It Up Forget the Price'' customer, it was not out of any sense of magnanimity. It was because I had reached the end of my rope with crowded stores, insufficient parking, rude salespeople and insulting prices.

In short, I am your plain old, everyday, ordinary shopper. If you see me coming your way, it's not to please you but to please me. Just remember one thing: I work hard for my money. If you want some of it, you had better work hard too.

DARREN J. DOBKIN Rockville