There's probably no blanket solution, really depends on your interaction with the buyer. They may also request a certain method. Not sure if you're talking about adding payment options directly on your site like an instant "buy now" button, or via contact.
For me, selling domains thru my site was always via contact and the PayPal vs Escrow decision was dependent on these factors:
- sale price
- trust factor after interaction with the buyer
- buyer preference
- buyer's geographical location
Sale price: High-value domains is usually Escrow. There have been exceptions one or two times, and it worked out ok. For low-value domains, I almost always direct buyers to an invoiced PayPal.. unless:
Trust factor: There's a weird feeling coming through about the buyer; based on say the email they use for correspondence, or the within the correspondence itself. As the seller you want to foresee potential issues and do what's best to protect the sale of your asset, even if it means taking extra time to guide the buyer with proper instructions for settlement.
Buyer preference: If the buyer indicates a preferred payment method that can incur chargebacks, I will acquiescence based on the two above factors.
Geographical location: Depending on where the buyer resides, or where you reside, there could be restrictions on what payment gateways may be used. Sometimes the only option may be via a 3rd party marketplace.
A buyer might also have never used PayPal, or Escrow or Dan or anything before, so be prepared to help out in that matter too, and waiting for their verifications and whatnot, if selling through your own site.