how would you feel if someone asked you for a free room at your hotel just for a night just so he / she can compare with a rival hotel before he / she can make up his mind on which hotel has the best room?
Here's my advice, do your research, find the person/company that you think can do your site (hint: make sure that particular company/person has a website and you can see their work, you can even try communicating with some of their clients, ask them how it is like to work with that particular guy), then ask them for a quote and decide which one has the best offer.
Back when we were starting, prospective clients would ask us for a design comp / sample layout before even having a contract signed, we were doing it because we were still trying to make a name for ourselves and i think we were naive but now we all have portfolios where we can showcase the projects we have done so people like you can see them, you see my friend, we are professionals now and we charge for every hour we work on a project.
By the way, if you are still undecided, just drop us an email (hello@watabelabs.com) and we will send you a quote but make sure that you are not looking for a cheap design because we don't do cheap or average, If you are looking for cheap don't even bother because we won't have any agreement. I think its time you guys top treating your websites as a one night stand kind of thing, It should be like a marriage, 'til death do us apart kind of thing' if you know what i mean.