Of the of the box AWS limits on EC2 Standard RI marketplace transactions for a single AWS account are up to $50,000 in Reserved Instances and up to 5,000 Reserved Instances.
Archera not only tracks these limits but also helps customers stay well below them in a few ways:
We recommend EC2 Standard RIs & Archera GRIs that are No Upfront so they are $0 listing just transferring the remaining commitment and not containing any upfront value that would count toward the $50,000 limit
We take advantage of instance size flexibility to sell fewer total RIs when we sell back. We modify an RI to a larger size before selling and this allows us to transfer a lower quantity over the marketplace. For example 64 t3.nano = 1 t3.2xlarge under instance size flexibility and so for most orgs it would take on the order of 10-years of using the service to hit up against the limit (at which point AWS can approve a ticket for a limit increase)
The limits are per-account rather than per-organization. This means even if the limit is hit (usually by a customer doing it themselves and hitting the limit before using Archera) its easily sidestepped by changing the purchasing account within the org from the master payer account to one of the sub-accounts as that account wouldn't have hit that limit