Hi for a cheap laptop to run qubes I recomend Dell m6800,
4 Cores, max. 32GB RAM, relaxed 17 inch screen for the vision impared.
The keyboard is shity but it is Quite expandable: DVD tray may be replaced with 3rd party hdd adaptor, if available.
Internal PCB-SSD (m2?) supported.
Quick swapable HDD 2.5 inch.
Displayport and some nice other interfaces.
PCIe-slot ? (Would need to grab it from the laptop pile).
Qubes 4.x runs with processors of amd64 arch with 32nm or smaller.
Opteron comes without PSP on 2nd Revision of 32nm processor.
3rd revision introduced psp (management engine of AMD, which is less “documented” than Intel ME (corna/me_cleaner and forks) )
1st Revision of 32nm Opteron has many bugs.
Use Asus K9DSE? Board and coreboot with qubes (I need to build it).
Back to the topic, go for <45 nm.