There was a post recently about starting up "rent a sysadmin." The problem is two-fold. How would you vet them apriori? After a while they could get reputation

There was a post recently about starting up "rent a sysadmin." The problem is two-fold. How would you vet them apriori? After a while they could get reputation I guess but you're handing over everything to the sysadmin. The second is that IMHO a good sysadmin is worth their weight in gold. So what would the caliber of the rent-a-sysadmin be given the short term and relatively "low pay."