Unless you really want a laptop, go for a gaming desktop PC, they are cheaper than gaming laptops and they generally last longer.
Other than that, it's up to how much you want to spend. You can probably get pretty decent performance in the game with a Desktop PC for $1200. The sims4 have gotten pretty CPU demanding over the years so I recommend getting something with a good CPU, that will cost more though ($1500+).
You can buy something cheaper than that, but I would recommend spending at least this if you play the sims4 a lot, might as well spend a little bit more money on things that you enjoy doing.