Network first, always. The coin matters less than where it runs, because the fee and the confirmation time come from the chain, not from the token itself. I keep a stablecoin set aside for renewals and purchases, and I never let the exchange choose the network for me, since the default route is usually the most expensive one. Before sending anything I check three things in that order: the network the receiving side actually accepts, the current fee, and how long finality takes there. For routine renewals I keep a small float ready so I am not converting at the last minute with a domain about to expire. For an actual sale I would not take a direct transfer at all. I would use an escrow service that settles in stablecoins, because it removes the argument about which network was agreed and who eats the fee. The coin is the easy part. The chain is where people lose money, usually by sending on the wrong one.
