I make my own prints, but I use archive quality paper and a profesional inkjet printer, and yes, it is expensive, but it cancels out my travelling costs for me to drive 250 miles everytime I want prints.
For printing artwork - Is it possible to use the photo quality inkjet printed on acid free Wausau or Vellum card stock and use Krylon "Make it Acid Free" paper protection spray to achieve archival quality?