serious question - how do you people afford all these mods?

I recently have been wanting to play the sims 4 (which is free on my MacBook) but then I look at the prices of the mods..and dang! How do people have so many installed? Is this just something that has been growing over the past couple of years or do y’all just set aside money specifically for the sims, because I might just have to do that. Does anyone recommend any must have mods? My last question would just have to be, are these downloaded though the same software/website where you downloaded the sims 4? Thanks in advance :)

UPDATE: Thank you everyone who helped clear my confusion, I had no idea there was a difference between the packs and mods so y’all seriously saved me a load of money I was about to spend on those. Thanks!