To quote ebay:
Instant Money Transfers
(such as Western Union & MoneyGram)
Not recommended.
eBay does not recommend the use of instant money transfer services. These services are designed to allow you to send money to family and friends - people you know and trust. While sellers may offer this option, they cannot require you to pay this way. If you suspect a seller is trying to commit fraud by insisting on payment through an instant money transfer service, please decline to use it and report the seller to eBay.
Risks:
Vulnerable to criminal misuse
Difficult to identify and designate recipient
Not traceable
Does not offer verification and cancellation privileges
Generally, no recourse is available if the item is not delivered as promised, even if you used your credit card to send the payment
Not covered under eBay's Standard Purchase Protection Programme.
Note: please use extreme caution when using such services, and decline to send money to sellers who insist on payment through this method.
I know that's worded for purchases, but same applies to selling.