@Matty8787 AC is a great game, elevated to incredible levels due to the phenomenal work of the modding community, delivering an outstanding amount of mods for just about anything out there. For the low price you can find the base game, any racing/car enthusiast would really be silly to miss such a great game, I highly recommend it and have many modding videos and tutorials on my channel if you want to get into it.
ACC on the other hand is a much smaller game in comparison with it's scope of just delivering on GT3 and GT4 content, but my god does it deliver. I'm only just really getting into now, which was kinda forced onto me due to trying to save money by cutting back on my iRacing sub and setup subs. I've actually been very surprised by how good it is now and currently playing through to try and build up my safety rating to enter the LFM (Low Fuel Motorsport) servers as essentially it's an iRacing structure but without the costs. I would really encourage you to try out both, but maybe the original AC with all the mods would be the most sensible money wise. I guess it's what ever fits your needs, but both will not disappoint what ever you opt for.
Talking of which, I think I'm finally picking up the heavier handling of ACC, had my most enjoyable race to date, ACC is really making me smile now when racing. Safety Rating is at 74 now, so just 6 more points needed to enter the LFM and get my license.