i Like both sims for diffrent reasons.
i Like Iracing because of the serious racing, statistics, racing with real cars, getting the feeling you are part of a group of drivers and not just one of the thousands that have bought a videogame. I like te realism of damage feeling when you scratch a wall or having a collission. In a LFS race the leaders fly away with 2 seconds or more each lap. in Iracing and special in the solstice the leader has a maximum of 20 seconds distance after 30 minutes racing. because you will be listed with drivers with skills that are almost the same as yours. i love the rating system, there are just a minimum of drivers that crash you for position or doing a kamikaze move, lets say like real. you realy have to practise and practise to get to the top of the field. and get the fastest laptime. on lime rock with the solstice i'm now close to 1.02 seconds after 200+ laps training. In LFS ( after 8 months brake ) i was close to WR in 4 races and back on my old level. It is a lot easier then Iracing to reach the top and stay there.
There are a few things in my opinion that can be changed like damage model and some physics but these guys are seriously busy with making it all perfect.
And about the money, yes it is a lot but you get a lot also. most of the time i use actions like a 3 month membership for 50% price. the cars and tracks cost a lot to but thats a one time spend. you keep them even when y'r membership is out.
I race LFS since 2005 and before that demo. i like the pick up races and everything LFS has to offer. ( drift, cruise, banger, demolition derby, autoX rallyX ) LFS is for me solid ground where you always can come back to have some fun races and competition. some time league .For serious racing i use Iracing.
At the moment i first need a new PC. mine is from 2003 and crashes everytime when it is getting difficult for him. after that a new membership for Iracing and the Ford Mustang FR500 + tracks.