Full disclosure:
I currently have a system (printers, calibration, software, and ,media) that costs as much as a small car. I print for my clients and offer print services to other photographers, including custom profiling. I'm lucky to live in a market that can support my business.
I guess I was an exception that actually found the online print houses less than adequate and I am able to now print in studio for a fraction of the cost at a higher quality, quicker, and with better control. I'll admit I had to get my head around it, but it wasn't that bad, and worth every penny. I'm a photographer first and printer second. 
Most online labs send sRGB files to their top of the line photo emulsion printers (Durst and Oce) removing image quality advantages. WHCC also only accepts JPGs. That just doesn't cut it for me, especially with larger images. For most people, sending in snapshots of grandma and the family BBQ it's just fine.
Regarding archival quality, if you look at WHCC's FAQ they actually use inkjets for their archival fine art program, not emulsion printers.
Anybody can print with stellar results for under $500 these days...just not in a wide format. Look for a pigment based printer and invest in some good paper. The new baryta and F-Gloss papers from different manufactures turn out amazing prints.
For anyone bored and really curious check out the books "Mastering Digital Printing" and "Fine Art Printing for Photographers". Great intelligent insight into what technologies would be best for you.