New or used? You can gat the 718’s as well. Even first generation T300 series (released 2019) will be a lot less than the current T350.

The 716 were released 9 years ago. The design has been refined since then. Titleist sells many sets with customized shafts. Finding a set with the best optional shaft for your game may be difficult. A large reseller like 2nd Swing can assist you with trying to find the best fit for used clubs.

Your decision is probably going to be budget based. The T350 is the current model most comparable to the AP1 and can be fit to a shaft that best matches your needs by doing a professional fitting. They will also carry the full Titleist warranty whereas picking up an older set of AP1 or T300 will not cover any problems you may have. You will have to rely on replacing irons by hunting down used ones through internet or second source sales sites.

AP1's are very good clubs but are a few generations older in technology. If you like their performance by all means play them. But, if you are looking for more advanced technology I would recommend going to a Titleist fitter and getting a head and shaft combination that fits your game. You can save a few bucks buying older sets like the AP1s if you get them thru a reputable retailer. Might be better, go see a teaching pro, get that handicap down then see a fitter. A few options to consider. Cannot buy game.

AP1's are very good clubs but are a few generations older in technology. If you like their performance by all means play them. But, if you are looking for more advanced technology I would recommend going to a Titleist fitter and getting a head and shaft combination that fits your game. You can save a few bucks buying older sets like the AP1s if you get them thru a reputable retailer. Might be better, go see a teaching pro, get that handicap down then see a fitter. A few options to consider. Cannot buy game.

Sounds like you're thinking of a used set. For what it's worth, I had the 714 AP1 and did not see any improvement with the 716 when they came out. I did see an improvement with the 718 version. Played them until about 2 months ago. Liked them so much I keep them for practice sessions. Pay more attention to the shafts. That's where you'll see the biggest difference.
If you're thinking about a new set, by all means please seek out a Titleist fitter. Be prepared though. You might lose a few strokes on that handicap.
Good luck with it either way you go.