Hi there,
I see a few options for you. Buy some watches and contribute some posts to build up your profile so folks will be more likely to deal with you and get the DD down the road after you have established yourself.
If you are set on a franken Day Date, search all the rep forums sales areas frequently looking for a member to member sale of a mymanmatt build or similar. They do come up from time to time. I sold one a few months ago. Just for reference nice DD builds are generally 1K+. Although you may run into the same problem M2M with folks being leary because you are new.
Try and connect with some of the senior members here and get one of them to vouch for you.
One of the issues you are running into is that people have filed Pay Pal disputes against members and kept the watch and the money, so many of us are less likely to deal with people we do not know or have not dealt with in the past.