Here we use the following notation:

• CNT — Center of network trade;
• PG — piece goods;
• AG — alternative groups of PG;
• NG — a non-alternative such group.

     Given:

• amount of investment, which is allocated for acquiring PG in Internet through CNT;
• one of two possible criteria of usefulness of PG samples, which are selected for their acquisition:
  • utility ratio for a sample of PG (relative criterion);
  • purchasing worth of a sample, that is equal to the product of its utility ratio by its cost (absolute criterion);
• a set of available for acquisition PG, which are divided into several categories;
• for each such category are given the number of PG, for each of them are set:
  • number of available for acquiring PG samples;
  • name and description of a PG sample;
  • its full cost (including delivery);
• formed by investor (an online buyer) several AG for PG, selected by him, and one NG;
• for each chosen PG is given a value of criterion of its sample usefulness;
• for each AG are set the minimum and maximum numbers of acquired samples of various PG, included in this group;
• for each PG of a single NG are set the minimum and maximum numbers of its acquired samples.

     Maximized quality criterion: total purchasing worth of acquired PG under given restriction on the amount of investment.