@JimHowell1970 is very kind in responding so often to requests for advice. Really. He's one of the mainstays here now. However, I'm going to take the liberty of contradicting him on one point in particular: this case thing, that... Mantis.
Yes, there's the price of the case and the relationship with the number of HPs available. But a case isn't just that: there's also its overall size, its materials, its solidity, the power supply, whether or not it has 1U rows, whether or not it can be linked, the general style, etc. And it's the same as with the modules, with the way they're choosen. As with modules, there are the technical features, there's also the emotional connection with the whole object, or even a brand.
4 years ago, I hesitated between several models of cases and the Mantis quickly became my first choice, but in the end I opted for Arturia's RackBrutes. This is a personal choice. The most important thing is to feel good about it. And there's nothing chauvinistic, I'm French and I prefer London to Paris. Ah... Wardour Street, Leicester Square, Baker Street, Hyde park, Speakers' Corner, and the best hot dogs in the world (there should be a thread about this)!
'On ne devrait jamais quitter Montauban' (Fernand Naudin).