1. Resumes are not a one-shot deal. You should be tweaking your resume for each job opportunity. And you definitely should be writing a new cover letter for every opportunity. Yes, it's time consuming, and yes, it's a pain, but if you want the job in this kind of economy, you need to look like you're perfect for it. Like a good fit in a suit, you need to tailor, tailor, tailor. Think of Tim Gunn's discerning eye. Be selective, persnickety even. It's worth the time.
2. I don't know what you're proud of, you do. Resumes aren't about job titles and duties anymore, they're all about accomplishments. What have you done for the world lately? Why should we care? When I critique, I like to ask a lot of questions about this, because so often I get a list of typical duties in resumes. Typical is just not good enough. You need to go beyond what is expected of you. I also hear so many people give up on this because they can't write a sentence like: "Saved Corp X $750,000 annually by doing blah blah." It doesn't need to always be about money.
3. It's cheaper, and you really can DIY. I'm always amazed that people will spend weeks watching home improvement shows, shopping at Home Depot, and laying hardwood floors themselves, but they won't read a basic overview about resume style and then take a stab at it themselves. Just get started and then ask for someone you trust to read it and share their thoughts.
3. It won't sound like you. I'm a firm believer in Plain English, in telling it like it is, and sometimes a professional resume sounds, well, too professional. Know what I mean? Are you really a "self-starter?" If you've worked for more than a year in your field, you probably know the industry lingo better than a resume writer anyway. Write with confidence, because you know your audience.
Need some overviews on resumes and job hunting? The Knock 'em Dead series is good and should be available for free in your public library. Give it a try, and then get another set of eyeballs on the document.
Good luck out there!