Digitize Artwork for Professional Prints

I have one original, full-colour piece measuring roughly 12" x 12" that I’d like turned into a high-resolution digital file suitable for gallery-quality prints. The final file must be delivered as a print-ready PNG... (Budget: $250 - $750 USD, Jobs: Art Consulting, Digital Art, Graphic Design, Image Analysis, Photo Editing, Photography, Photoshop, Print Design)