Dear Sir/Madam,
I've read your job post and I believe that I could be the right guy for the job. I've given you a competitive price not because the work provided will be of a low quality, but because I'm currently living in Cambodia so my expenses are quite low. My English skills are great so I can assure that there will be no spelling errors. I'm not busy for the next few hours, so if you'd like I can begin this task right away!
Thanks in advance for your time and consideration, I look forward to discussing this with you soon!