Hi ! I want my rx8 orange and black exactly like in this photo. do you know if its better to wrap or paint this ? and what would be the cost of it... also should I do it myself(how many gallon/wrap paper I need?) or go in a shop...

 

Unless you have experience don't DIY.
If you want a good durable paint job it would likely be several thousand $ at least.

Do you just want to do the exterior, or do you want the interior jambs and sills to match?
That requires the interior to be removed.
What about under the hood and engine bay?
You would be without your car for about a week.

If you just want to do the exterior and don't care what the rest looks like, then a wrap probably.
Plus if you don't like the result you're not married to it.
A cheap sand and overspray might not give satisfactory results.