Mergers are declining in number but rising in cost.

Corporations this year are paying more and getting less when they buy each other out, according to a report by the research firm of W. T. Grimm & Co. The number of mergers and acquisitions tumbled in the first six months of 1987, but the total dollar value continued to rise. Major deals boosted the 1987 price tag to a near-record level, with 17 mergers valued at more than $1 billion, compared to 10 the year before. The slowdown in the number of mergers is expected to continue through the year, but the dollar total will continue to rise due to the increased prices being paid.