[TYPO3-shop] restrict discountprice to articleID

[G.Unger]

hello list

how can I restrict the discountprice to the articleID?

getDiscountPrice=1
discountprice {

  10.type = count
  10.field = price
  10.additive = 1
  10.prod.1 = 30.95
  10.prod.3 = 27

}

i tried
- itemnumber = 1 <= uid od the article
- sql.where and where ... like 10.sql.where = and even 10.where = ... 
followed by sql
- played around with pricecalc

want I want to acheave:

I want for a dedicated item to be able to set pricegroups, e.g.

articleUID 1
qty 1 = 30,95
qty 3 or more = 27,00
qty 10 or more = 25,00

thx for your input

GUIDO