https://www.corsair.com/us/en/corsair-build-kits

Was looking at the core build kit for about 1.2k usd

Currently using a Dell G7 laptop and looking to upgrade to a desktop

imo spend the extra 800 get the 4070ti build but that's just my take on it, the 4070ti would smoke most games and be more future proof

Would I be able to upgrade in the future with "core" build?

Aka buy a 4070ti elsewhere and upgrade down the line

By the time u upgrade, 4070ti would be old and most likely be 5070ti or something. Technically you can still upgrade in the future if you build the computer well, but based on the specs of the 1.2k build, the 550 PSU wouldn't be ideal and you'd have to buy a better quality psu and 750w would be more ideal.

With that said, even the 1.2k build is a huge upgrade from your Dell laptop. Depending on the games you play, the 1.2k should be more than enough.

I paid almost 2 grand for the lap top lol and the game I play are mainly RuneScape,world of warcraft, and CSGO

The Dell gz has an i7hexacore and I have en external monitor and external SSD just use it as a desktop basically but most PCs I spec check still can't compare and I bought this laptop almost 6 years ago

Laptops usually cost more and perform worse than desktops because you're paying for portability. Also heats a lot less on well built desktops.

For those games the 1.2k is more than enough and overkill. If you lasted 6 years on the laptop, the desktop should last you a decade assuming you play those type of games and not branch out to more heavy demanding games like Witcher etc.

You Didn't hear this from me, But Corsair is going to be doing a Warehouse Clearout in June.
Would be a great time to Dip in on some Mega Sales. ( If you can wait 3 months ).