Re: Blah.
"...but how much TB of it will cost? "
Well seeing as you can get SSDs that are faster, more resilient, newer generation, same or better make to the ones that HP will sell you but cost about a third of the price, expect to be paying many thousands of dollars for a TB.
So why not use the much better third party SSDs? Ah, because HP Proliants will detect this and will put a permanent amber fault light on the box, and a permanent fault report in the system management tools and will often refuse any support despite having a support contract because they know there are third party drives in there (regardless if the problem could be classed as drive/storage related).
It wouldn't be so bad if it was just a 10~20% manufacturer premium but 300%! Pah - I've got amber lights on my servers!