Not directly related to the SQL Server side, but it is also worth pointing out that on the MS documentation pages, for most applications, it is recommended to use the Currency datatype instead of Double or Decimal.

The two reasons given are:

1) Memory usage - Currency is a 8-bit datatype, thus using the same amount of memory as a Double

2) Precision - Currency has Decimal level precision up to 4 decimal places.

So, if you need more than 4 decimal places and you aren't concerned with precision (i.e. Office Space), then a Double may be more appropriate.

On the other hand, if you need more than 4 decimal places and need to retain precision as well, then a Decimal is more appropriate.

That being said, the draw back to using the Currency data type is you have to be sure to adjust the format of your field (after you've saved it) to remove the currency symbol. I.e. by changing format to Standard, General, Custom, or another format.