I have only bought my tickets from 3rd party sellers since I started going back in 2014 from Undercover tourists. Frankly, I have never seen the benefit of getting a package deal as opposed to getting a room-only reservation and separate tickets.
Until Disney started putting expiration dates on tickets, there was really no downside to buying tickets ahead of time and using them even a year or two later. You'd save money with the 3rd party discount you got PLUS even more since they were raising ticket prices yearly.
I have 4 days left on the old "10-day park hoppers with the no-expiration option' (that they stopped in 2015) that I used for 3 separate 2-day trips in 2014, 2015, 2017 at a way more affordable price than getting the tickets as I went. Those tickets cost $75/day . .when it costs on average over $100/day to go now (when you go for 4 or less days). That is 25% savings (that will just get bigger the longer I hold onto the tickets). While it was a lot of money to spend at once way back in 2014, it's not like that there is much I could have invested that money in to get that sort of return easily.
These money saving techniques (of buying tickets in advance from 3rd parties) are a thing of the past. Which is probably Disney's intention. They don't want tons of people holding on to tickets for years (and thus having keeping track of them in the system) and going to the park for half the cost of new tickets.
I'd still be happy to give Disney my money now to save money in the future, but they obviously don't want that anymore.
Disney just wants to know exactly when people are coming and for how long.
I'm sure they will increase the prices of Annual Passes (that don't have blackout dates) as well to discourage their use and push people to this new "plan ahead" pricing structure -- as owners of those throw these crowd predictions out the window as they can show up at any given time.
Unless you can snag free dining or something similar, buying from UT or PS and getting room only is always better. Or at least it was.