I've done the blue cooler (red didn't seem work well) batch sparge for many years along with BIAB. Neither of which is very expensive and makes great beer.
http://www.dennybrew.com/I also do Mr. Beer kits, which if you're just starting out might not be a bad investment. The quality, customer service and supply chain management has *vastly* improved over the years to the point that out of the 20+ kits I've done in the last couple years I've not had a single one that has been out of date (all were 2+ years before expiration) or missing ingredients. They're easy and fun to make, plus they make great beer.
Something like the Grainfather, Brewzilla or Anvil Foundry also looks appealing but ATM everything I have works well. If you have your heart set on stainless all in one these are probably your best bet.
A true 3 vessel HERMS is probably 4-5k+ plus FV, ferm chamber, etc... that's a large investment for a first time brewer and it won't make your beer taste any better.
https://spikebrewing.com/pages/spike-systemsThere is a very slight learning curve to brewing, albeit more of a knack but a smaller cheaper setup will expose you to the in's and out's without the expense.
Things like Low Dissolved Oxygen can be addressed as you build your system, unless you want to spend 10-15k for a LODO setup...
https://conical-fermenter.com/low-oxygen-brewing/