SSAS -> MDX -> Create a price comparision against resellers
If you have the following database schema with Date, Product and Reseller dimensions and a price fact table:

create table DimProduct (
       ProductID    int not null
      ,Product      varchar (50)
)
go

Create table DimDate (
       DateID    datetime not null
      ,MonthID   int not null
)
go

create table DimReseller (
       ResellerID   int not null
      ,Reseller     varchar (50)
)
go

create table FactPrices (
       ProductID    int not null
      ,ResellerID   int not null
      ,DateID       datetime not null
      ,Price        money
)
go

insert DimProduct (ProductID, Product) values (1, 'Widget')
insert DimProduct (ProductID, Product) values (2, 'Dohickey')
insert DimProduct (ProductID, Product) values (3, 'Whoflungdung')
go


insert DimDate (DateID, MonthID) values ('2012-01-01', 201201)
insert DimDate (DateID, MonthID) values ('2012-02-01', 201202)
insert DimDate (DateID, MonthID) values ('2012-03-01', 201203)
go

insert DimReseller (ResellerID, Reseller) values (1, 'Braise and co')
insert DimReseller (ResellerID, Reseller) values (2, 'Cocost')
insert DimReseller (ResellerID, Reseller) values (3, 'Walls Mart')
go

insert FactPrices (ResellerID, ProductID, DateID, Price) values (1, 1, '2012-01-01', 10)
insert FactPrices (ResellerID, ProductID, DateID, Price) values (1, 1, '2012-02-01', 9)

insert FactPrices (ResellerID, ProductID, DateID, Price) values (1, 2, '2012-01-01', 10)
insert FactPrices (ResellerID, ProductID, DateID, Price) values (1, 2, '2012-02-01', 10)

insert FactPrices (ResellerID, ProductID, DateID, Price) values (1, 3, '2012-01-01', 10)
insert FactPrices (ResellerID, ProductID, DateID, Price) values (1, 3, '2012-02-01', 11)

insert FactPrices (ResellerID, ProductID, DateID, Price) values (2, 1, '2012-01-01', 10)
insert FactPrices (ResellerID, ProductID, DateID, Price) values (2, 1, '2012-02-01', 10.5)

insert FactPrices (ResellerID, ProductID, DateID, Price) values (2, 2, '2012-01-01', 10)
insert FactPrices (ResellerID, ProductID, DateID, Price) values (2, 2, '2012-02-01', 9.90)

insert FactPrices (ResellerID, ProductID, DateID, Price) values (2, 3, '2012-01-01', 10)
insert FactPrices (ResellerID, ProductID, DateID, Price) values (2, 3, '2012-02-01', 11)

insert FactPrices (ResellerID, ProductID, DateID, Price) values (3, 1, '2012-01-01', 12)
insert FactPrices (ResellerID, ProductID, DateID, Price) values (3, 1, '2012-02-01', 10.5)

insert FactPrices (ResellerID, ProductID, DateID, Price) values (3, 2, '2012-01-01', 10)
insert FactPrices (ResellerID, ProductID, DateID, Price) values (3, 2, '2012-02-01', 11)

insert FactPrices (ResellerID, ProductID, DateID, Price) values (3, 3, '2012-01-01', 10)
insert FactPrices (ResellerID, ProductID, DateID, Price) values (3, 3, '2012-02-01', 10.5)

go


Create a cube with Date, Product and Reseller dimensions and a SalesTrends fact table with a single metric 'Price'.  The MDX query below will produce counts of products for which the price is increasing, static or decreasing in a given period.

with 
member [Measures].[Delta]
    as [Measures].[Price] -
       (parallelperiod ([Date].[Calendar].[Month]
                       ,1
                       ,[Date].[Calendar].currentmember)
       ,[Measures].[Price])

member [Measures].[Rising]
    as count (filter ([Reseller].[Reseller].Children
                      ,[Measures].[Delta] &gt; 0))
      ,solve_order = 20

member [Measures].[Static]
    as count (filter ([Reseller].[Reseller].Children
                      ,[Measures].[Delta] = 0))
      ,solve_order = 20

member [Measures].[Falling]
    as count (filter ([Reseller].[Reseller].Children
                      ,[Measures].[Delta] &lt; 0))
      ,solve_order = 20

select {[Measures].[Rising]
       ,[Measures].[Static]
       ,[Measures].[Falling]}
    on columns 
      ,[Product].[Product].Children
    on rows
  from [SalesTrends]
 where ([Date].[Calendar].[Month].[201202])


The query calculates the delta from the previous period, and calculates three metrics for rising, static or falling based on counts of resellers where the delta is positive, zero or negative.  Note that the prices will aggregate in strange ways if you to calculate this at anything but the lowest grain of the underlying fact table.