If multiple cells contain value then add value

Trying to think of the best way to sort this problem!
.
I have a spreadsheet with a list of customers that have purchased a vehicle.
Along side information I then list whether they've collected the vehicle and if it has any EXTRAS on there (3 possible for each vehicle)
.
Each extra has a worth of £25
Each car sold has a worth of £15
.
In the car sold list I currently have this formula:
.
IF(A1<>"",15,"")
.
Where essentially it adds 15 everytime to the car sold cell once a collection date (A1) is present
.
I then have a grand total cell that sums all £15's in the cars sold column together with a simple SUM formula
.
Now my question is, is there a way for me to use a similar IF formula where if there's text in the extras cells to sum together in one column
.
I tried
IF(A2<>"",25,"")+IF(A3<>"",25,"")+IF(A4<>"",25,"")
.
Which only counts if there's something in every of the 3 extra cells, is there a way I can sum only the cells that contain text and ignore the others that do not with a if false formal perhaps?
.
Cheers