Without knowing your game or seeing your swing, the best advice I can give you is if you're left handed - get a left hand driver, and if you're right handed - get a right hand driver.
Seriously, there are too many variables between what we play and what you play. All Titleist drivers are top of the line, but designed to fit different swings. The specific model is just the start. The shaft choice is what will fit you more than the model.

100% agree. 19 handicapper and almost 80. Always get a fitting. Don't waste what little retirement income I have.

Adding to Barry and Chuck's fitting thoughts, I strongly suggest doing it outdoors so that ball flight can be observed. I am not a big fan of hitting into a net and letting the monitor tell me what is happening even though the current launch monitors present useful information. A true fitting professional might also be able to give you some information about what your swing is doing or might need adjusting to maximize a new to you driver. It will be difficult, though, to get a fitting for a prior generation product as most fitters return the obsolete models once new ones are introduced.

So many times, I see golfers tell the fitter what they want/need. Most of the time, the fitter will be able to show the golfer what performs best and why. Trust an experienced Titleist fitter. They go through a strong training program to help dial in the variables of the new products.

I can understand the notion of saving substantial $$ with a pre-owned or demo club. You may or may not find one that suits your specs (shaft, primarily). If you spend more for a new/current model driver, you won't shouldn't need to upgrade for at least a couple of generations (WANT to upgrade is a totally different topic!).

Good fortune to you!