Ideas....

Having differernt AR's for differernt purposes means a choice needs to be made before a build or purchase.

Do you want something Tacti-Cool or CQB
Maybe long distance shooting or accuracy is more important than all other factors.
Maybe an investment.
What about an alternative caliber.

16" carbines or maybe a 9mm carbine will fill the "Cool" or CQB

1:7-8 twist for heavy bullets with a 20-24" flat top chrome-moly or stainless heavy or bull barrel with a trued upper reciever should fill long distance and/or accuracy department

AR pistols or SBR's make good investment pieces

There are so many alternative caliber rifles still in your price range:
17 Mach II, 22lr, 9mm, 40S&W, 10mm, 45ACP, 17 Remington, 17 Fireball, 17 Olympic, 17/223, 20 Tactical, 20 Practical, 221 Fireball, 204 Ruger, 22PPC, 223WSSM, 6x45, 6mmAR, 6mmPPC, 243WSSM, 25/223, 25WSSM, 6.5AR, 6.5/243WSSM, 6.8SPC, 7mmWSSM, 300-221, 30HRT, 7.62x39, 300WSSM, 338WSSM, 357 Auto, 358WSSM, 458 SOCOM, 450 Bushmaster,
etc., etc., etc.

I'd hold off on optics and ammo.
They will still be available after November.
With $1300 to get the most bang for my buck I would get 2-3 stripped lower recievers and build a couple with rifle/carbine kits.

Lower $120+
Kit minus lower reciever $460+
Complete Rifle Build $580

That said I have been down the complete rifle buy, the build route and the custom rifle from nationally accredited and dedicated AR target/varmint rifle builder.
The best bang for the buck as far as sale-ability at a later date is the build.
To most buyers they demand just as much money as a store bought rifle.... particularly if the manufacture of these rifles becomes banned.