Using set analysis in conjunction with variable

[GrantBooth]

I've got some measures which are quickly getting unwieldy and I'd like to start using variables instead, however I've got some questions about using set expressions.

I have variable v.Amount which is very straightforward, -1*Sum( Amount)/1000

Is it possible to add set analysis and a variable in conjunction? What I mean is that I would like to be able to have

v.Amount for <ProductType = {'Budget'}>}, rather than typing -1*Sum({<ProductType = {'Budget'}>} Amount)/1000.

Using dropdowns isn't appropriate because there's instances of {<ProductType = {'Actual'}>}  and {<ProductType = {'Forecast'}>}  appearing on the same sheet

[Digvijay_Singh]

May be achieved using parameter in the variable - 

Variable 1 

Name - v.Amount

Value - -1*Sum( $1 Amount)/1000

Variable 2 - vsetExp

Value - {<ProductType = {'Budget'}>}

Expression in text box I tested -

$(v.Amount($(vsetExp)))

It shows - 

 in expression editor

[GrantBooth]

Not able to get this one to work, the expression -1*Sum( $1 Amount)/1000 creates a error