For me I’d say computer hardware or parts would be more used term not a great lover of .biz they are pretty hard to get to list high and stay there…? Not sure if someone that sells pc bits would be more web savvy i.e. prefer higher tld or cctld or not. Try just a blanket email to retailers there are plenty out there might get low £xxx, Or if it list sure you could get a small regular income from some sort of affiliate
If you do register more obscure TLD’s or any TLD you might want to look at doing it with other companies other than 123 reg you could save yourself £ 5 -10 pounds per registration…. A lot of the uk companies are fine for cctld (uk) But not competitive at all with TLD’s