Enom integration via domain mapping setup problems

I'm setting up Domain Mapping plugin. I have set up and got working the mapping section and am now trying to add direct purchasing via Enom. I think I've got things mostly setup with Enom, but when I try to test buying a domain it always returns:

[testsite.com] is not available to purchase.

I have set up an account with Enom, added my details to the plugin and whitelisted my I.P. address in their test environment. I haven't added credit card information or added any credit with them yet.

Do you need to have a live account for this to work?