@ssaunders474 I found a few options for you; if no one else weighs in, these will certainly play TS3 with all packs on high settings.
This one is on sale for $650. It's a mid-level desktop, not really suitable for intense gaming, but it's a good place to start, especially if you want to save money:
https://www.newegg.com/Product/Product.aspx?Item=N82E16883101354&ignorebbr=1&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-Gaming+Desktop-_-N82E16883101354&gclid=EAIaIQobChMImujnqq313gIVkR-tBh2zXAK6EAYYASABEgLfCPD_BwE&gclsrc=aw.ds
This one is also from Acer, priced at $768 and a bit of an upgrade:
https://www.amazon.com/Acer-Aspire-Desktop-i7-7700-GX-785-UR17/dp/B01N9VCGN8/ref=sr_1_4?s=electronics&ie=UTF8&qid=1543346045&sr=1-4&keywords=computer&refinements=p_n_condition-type%3A2224371011%2Cp_36%3A60000-90000%2Cp_89%3AAcer&th=1
This one is $794, and its reviews are very good (better than the two above) except for the cooling—you'd need to make sure you had sufficient airflow during long gaming sessions:
https://www.amazon.com/CYBERPOWERPC-Xtreme-GXiVR8060A5-i5-8400-GeForce/dp/B0757DVF4Z/ref=dp_ob_title_ce
These all have 8 GB RAM but can be upgraded if and when you want. TS3 doesn't need more, but in the future, you may decide you need it for other purposes.
None of these come with monitors, but you can buy one easily enough at Best Buy, Walmart, etc. And you might want to check out the displays in person, since you'll be the one staring at one of them. You don't have to get an expensive model, either; it's easy enough to upgrade later.
Finally, when you do get your computer, you'll need to take steps to limit the in-game frame rates. TS3 has no fps limiter of its own, and all these cards are powerful enough to damage themselves from overwork if fps isn't capped. It's very easy to do, but there's really no point until you've set up the computer.