Is there a secret sauce to buying RIA?
I disagree with your recommendation specifically for the RIA 1911. Now these days the Turkish ones can be found for the same price but with better metallurgy.
Many of the long-term RIA owners I know would keep having their pistols shed parts, mainly with external controls like the grip safety, thumb safety, and slide release break. Another one I knew had a full length tactical 45 (straight mainspring housing, Novak type sights, guide rod) not function and kept jamming against a Norinco and modern Colt (2010s era pre-CZ) that used the same ammo and magazines just fine.
i don't recommend the gimmick tactical ones. bare bones RIA 1911A1 GI-style in .45 is 100% series 70/80 compatible and easy to fix if required. S&W, Springfield, Ruger, Remington 1911s are all good too to varying degrees and features (i like external extractors on odd calibers or if you use a lot of defensive or wildcat loads, otherwise internal extractors work fine for 99% of use cases that aren't brittle shitshows like early para-ords or kimber carry pieces).
ACT mags, Mec Gar mags, et c run fine in RIA for good pricing, wilson combat, chip mccormick for fancy people. Dan Wesson 1911's are great as are some of the more boutique builders but this is someone asking for a gun at a price point that isn't breaking his bank. for the money asked, a GI style 1911 from RIA is a lot of gun. Tisas can work too, but they don't have the track record imho compared to RIA/Armscor.
that being said, my experience with RIA is only a couple of decades, and i sell them regularly and repeat customers don't have much problems except with the MS model or some of the fancier tactical ones that aren't using GI parts (the factory in Manila makes pretty much only GI parts with a few exceptions, the tactical ones are MIM and imported from elsewhere (turkey, india, saudi arabia, myanmar, et c) and have some weird tolerance stacking issues since their from production lines for guns that are local to those markets and not the ones Armscor makes.
as always, if you can inspect a gun and shoot it a mag a two and get a good feel for anything loose or odd, that's the best situation. the "no brainer" buy for the money imho would be a S&W E-series 1911 or a Ruger SR1911. yes, it's more (perhaps far more than the budget) but they certainly are "duty-ready" if that's your thing. Tisas is as good as RIA imho since they make the entire gun, even on the fancy models. Girsan not so much a fan of their 1911's, although my experience with Girsan Beretta 92 clones are pretty good - as good as the PT92 and PT99 imho if we're taking Beretta 92 clones.