They denied having a PS4 / XOne version in the works as well when GTA 5 launched 2 months before PS4 / XOne launched. I bought it a year later for PS4 instead of playing it early. This time GTA 6 should still launch well before the next generation comes out, but there are already rumors it will be delayed to 2026. No idea how much of a hardware sales boost you can get 5 / 6 years into the generation.

Consoles aren't really dropping in price anymore, but there are plenty second hand options. Consoles sales seem to get more front loaded with the prices staying high. GTA 6 will give a big software boost anyway, dunno how many people will buy a 5 year old console for launch price to play one game. If you haven't found a reason to own either PS5 or Series yet, seems kinda expensive just to play one game.

Anyone have any idea how much GTA5 boosted ps3/360 sales in September 2013 if at all?

If it was about reaching 45 million, i absolutely would say "no".
But 40 million is maybe doable. Thats a hard question to be honest.
I guess, I still rather go for "no"^^

I'm sceptical of how much GTA6 will boost Xbox in particular as PS will be the preferred place to play as the more popular console.
It will cause a bump, but I don't expect a sustained boost.

Absolutely.

Yep, they got up by 2.5 times in the week GTA 5 launched, with almost getting to their previous levels in the following weeks, and then quickly got up again by the holiday boost by november. Monthly wise, they just doubled their sales in september compared to the previous months that year.

PS3 and 360 were a lot cheaper by then of course, but Series S should get a nice boost at least. Maybe the PS5 will finally get a price drop when the pro is out.

Should be enough to secure 40M+ with GTA 6' launch.

That shows the power of GTA then. I suppose some customers thought it was worth getting cheaper on the way out consoles instead of buying the about to release ones and hoping GTA V would get a port.

PS4 never had backwards compatibility, Xbox One didn't get it until 2015. And of course, the ports of GTA V took until later 2014. Not to mention Xbox One was $499.99 USD with disastrous word of mouth about the removed features like online check-ins and used game debacle and such nearing launch. 

By the time GTA6 comes out, which might not be til 2026, Xbox Series may be so dead in the water that not even GTA can help much, similar to how not even Mario Kart 8 or Smash Bros 4 could sell the Wii U.

Once a console gains a bad reputation, especially the infamous "no gamez" label, it's extremely difficult to turn it around. A few have managed to do so, like 3DS and PS3, but that was only through a herculean effort. For most, once the rot sets in it can't be undone.

If you mean MK8 and Smash 4 couldn't save the Wii U or get it GameCube levels or above, you're absolutely right.

They are the two games that got me to buy a Wii U, and without them I doubt the Wii U could've hit 10 million (it finished at 13.56 million). That's how dire things were, and I don't even think the Mario platformers and Super Mario Maker would've been enough to get to 10 million without Mario Kart and Smash. 

The potential GTA VI boost for Xbox Series is tough to predict because of timing. A 2026 delay would probably kill any big boost for Xbox, as I really think the Fifth Xbox will be out November 2026.

If Xbox goes for broke and gets Series S permanently down to $200 USD and Series X permanently down to $300-$350 USD by the time GTA VI launches, that could help.

But yeah, Xbox can't count on a 10 million boost from GTA or even a 5 million boost. 

I think it will just about get 40m but 45m is the absolute maximum based on how it's currently selling and let's be honest it will continue to decline.