Ok here is the thing...first of all, are they on sale? If not, then I would consider different colors that all the stores have out right now. I have heard that these pumps are pretty popular. They have been around for quite some time now. I have not heard of any problems with any valentinos. I own several of the bow pumps myself and love them. Having said that, you should consider the following:
1. Are they your style? If you love them, go ahead..but if you are unsure then don't buy them.
2. Will they go out of style? No probably not, they are a signature valentino pump and have been around for some time now.
3. How much wear will you get out of them? Everyday? Occasional?
4. Have you tried them on? I think comfort is the most important factor to consider here too. And Valentinos are comfortable, at least in my opinion.
Hope that helps!