Shopkeeper

I am currently experimenting with shopkeeper. I am crossing some difficulties now.

I have a product that can be paid directly or in terms.
So it’s 100 dollar or 25 dollar per quartile.

But now the problem.
I have made a dropdown that has:
--PAYMENT--==
||Pay at once==75
||Pay in terms==0

And in the price TV, i have typed in 25.
This works. But when you select the product, to pay the full price at once. And you add the product in the basket. The basket gives 25 dollar for the product. But in the total it’s 100.
This is logic because the basket row is set as [+price+]. So nothing is calculated.
But how can i do this? Because [+price+] is for the user very confusing.


2nd question.
When you select something from the dropdown. You see it under the product title.
Example:
Keyboard
color-red, pay at once(75)

How can I remove the "pay at once(75)" and only show color-red?