How to present as simple as possible product page with 3 categories that have more subcategories and for all one price?

I have to design MVP (as fast as possible) for one online SAS. Nomeather the subcategory of product the price is the same. I named all options anonymously because of NDA. All i can tell, that category is a kind of "trade" and subcategory is a concrete product type. It will be all together about 20 products - so there is no sence for making search engine.

On this LP user has to decide what he wants to buy. I have presented IA on mockup below. Please give me some other possible sollutions suitable for RWD. I have no time for tests so i need to decide by my own what will be the simpliest solution. I have problem with this what i presented, that he is lookign at too many options. On the other hand if i hide subcat, he will have to open each cat. to see if that what he is looking for is under that main category. It is also not clear that the price iwill not change depending on what the user will choose. The price is the same for all.

What is important that user can't choose category, because it is not the product. Subcategories are products - each one is totaly different, there cant be any other division for types.

Please help, send soem links - benchmarks, i couldn't find any examle same to mine.If u know please send:)

State 1: (before user has choosen subcategory)

^{download bmml source – Wireframes created with Balsamiq Mockups}

State 2: after user has choosen witch product he wants i that the next button will be enabled.