If you are doing a lot of loading and shooting then they are worth the extra cost. If you only shoot a couple hundred rounds a year and don't mind relaxing a little bit as you load with a turret or single stage press then they aren't.
Back when I was shooting quite a bit I thought about getting a 550 but kept putting it off telling myself that I enjoy the peace and quiet time of sitting down at my turret press and punching out rounds one at a time so I never did buy one. Anymore I break up my loading duties in three or four steps. I'll size and deprime the cases and throw it into the tumbler for a day. Then I'll sit in front of the TV and prime all of the cases with a Lee hand priming tool. Then I'll get down to the press and automatic powder dispenser for the rest of it.
Jim is correct. You really have to shoot a lot to justify the cost.
I have some friends that travel year round to shoots all over the country and have several Dillons setup for each caliber they shoot. The whole family shoots, so they need the ability to load a lot in a short time.
I don't shoot much competition anymore, except for Bulls Eye PISTOL. I shoot about 200 rounds per week of .38 in my match pistol. I reload with a RCBS turret tool and spend a couple of hours a week in a very relaxed atmosphere. When I was cowboy action shooting in competition, I shot a couple of thousand rounds per month in practice and matches. I used the same RCBS turret, just changed turret plates setup for different calibers. I could load everything I needed in about 3 to 4 hours a week. This includes case prep also
When my Dad and I shot ATA trap, we didn't reload for it. Dad owned a gun shop and we bought shotgun ammo by the case wholesale, so we didn't really need to reload for trap shooting.