fixed price, select x producs

[jenni123]

is there any module out there that i can install that will let my users do the following:

 

example: 

 

Price is 300, (300 is added once first product in category is selected)

 

and for those 300 the user can buy 15 products, (user can select whatever product they want from same category as first product) but does not have to select 15. can stop at 10 and checkout with only 10 products. so the price is 300 no matter if 1 or 15 products.

 

so maybe a different fixed price for another category/products. 

 

is this maybe possible in native PS?

 

Thanks in advance!

 

Regards