For Christmas a partridge is now $5

For those who would like to send their true loves the same gifts cited in the Christmas carol ''The Twelve Days of Christmas,'' it will be expensive.

Hugh Gee, in his investment advisory letter Money Power Confidential, calculates the gifts this year will cost $31,887.03, up 9 percent from last year. Mr. Gee called up some California game-bird breeders and found a partridge now costs $5, compared with $4 last year. Pear trees are $10, up from $7.50. The most expensive day is the seventh, when seven swans a-swimming will set you back cheaper items are geese, down 11 percent, and French hens, down 2 percent. He also reckons the expense of hiring maids, dancers, lords, pipers, and drummers, along with the cost of maids' uniforms and dancers' tights.