Multi Selection drop down list with cost calculation

Hi all!
I am pushing the limits of my knowledge in trying to get a formula that will search for particular items that have been selected from a multi selection drop down list and calculate the cost associated with those selected.

I have come up with a formula that works, however, I don't know how to condense it correctly, if possible, so I don't exceed the character limits when I add all the items that are possible.

I have posted a brief sample worksheet that shows what I'm talking about. However, I didn't add the multi selection box in the sample (I just used the wording that would show up).

In the sample, Cell B4 is the actual item selected. In D4 it lists any accessories or modifications that is added or changed to the item in B4. D4 is the multi selection drop down list as more than one change can be made to the item. In cell E4 I need a formula that can search D4 and calculate the cost based on the prices listed (in this case) lower on the sheet. In my actual workbook, the price list is on a separate sheet within the same file.

Right now I am using the following formula in cell E4:
=IF(ISNUMBER(SEARCH(A19,D4)),(F19)*C4+IF(ISNUMBER(SEARCH(A20,D4)),(F20)*C4+...

This works great as long as I don't have a long list of accessories or modifications. However, I have 18 different ones, at this time, on the actual file and the formula is too long. Anyone have any options or tricks to make this work? I think this is my last hurdle to finish this particular project, which I will be proud of when I'm done.
Thanks in advance for any guidance or direction you can provide!!
Lena

Thank you for the information. My issue is I need to be able to clarify which item gets what changes. I have seen a "Popup" list box with the option to check boxes of desired changes before. Is that a possibility?
I don't know what the technical name for that is if it is possible. Any direction would be greatly appreciated. Thanks again

After some research and "playing" with the form I am trying to create, I have gotten a little further than when I first asked this question. I have attached a snippet of the form I am creating and how it works in the actual file now. My question is once the user selects the "modifications" they want for each item, I would like to add code that would find the "true" selections and sum the price(s) of those selections in an adjacent cell.
Let me explain the process:
The user puts in an item and then the quantity. If the user tabs or clicks on the modification cell the user form automatically opens. The user can then select the options and click apply or cancel out of the form.
At this point, when the user selects the modifications and clicks apply, the "mod code" for each is posted to the active cell with a comma between each "mod code".
I have found the "offset" code and feel that is going to be part of my resolution, but I am having trouble putting it together correctly with sum.
Any help would be greatly appreciated. Thanks in advance!
Lena

That's where I fall short. I'm not having any luck setting up the correct code to the apply button.
The code I am using to record the selected mods in the active cell is below.

Myvar = ""

For x = 0 To Me.Access_Mods.ListCount - 1
If Me.Access_Mods.Selected(x) Then
If myvar = "" Then
myvar = Me.Access_Mods.List(x, 0)
Else
myvar = myvar & ", " & Me.Access_Mods.List(x, 0)
End If

End If
Next x

'place selections in worksheet into current active cell'
Worksheets("sheet1").Activate
ActiveCell.Value = myvar


I am assuming I need to have a code similar as the sum would only be calculated if the mod is selected, but I just can't get it to work out.

I am also assuming I would use a similar code using "offset" to get the total price to be documented in a certain cell.

Thanks for any help you would provide!
Lena

Was this ever solved? I am having the same issue. I have a table of costs by service as well as a multiple selection dropdown. I need it to sum the total cost based on what is selected in the dropdown.