I also worked for "the man" and ALWAYS sent my designs out to VistaPrint, it was good quality work and really affordable. The only drawback is the 2 weeks it takes to actually get them in the mail. At my local pritner, I can get my prints in 2 days.
I personally ONLY offer printable downloads to customers. I have noticed that there are mostly just 2 types of etsy sellers in this category, the ones who sell digital files, and the ones who sell you the printed package.
The reason I chose to only sell digital files is because I don't have the time to be dealing with print. It takes lots of time to handle all that goes into getting these printed. I think people find the most success if they have their own printer and are able to do everything themselves.
I have had some customers who need a recommendation as where to print, but most of the customers who are in need of printable designs either do it on their own printer or have them sent to their local printer.
If I charged my Etsy customers the price of what my local print shop costs to print, they would think I'm nuts.
For me, I just can't justify charging my clients that price of my local print shop or tell them they have to wait 2 weeks for vistaprint to get them their invites.
Selling the digital files works just perfectly for the kind of work that I do. I wouldn't completely nix that idea from the get go. You could always try selling digital files first, and see how it goes, and then try selling printed versions.
Good luck!