Optimize Slow-Loading PDF File- 3 similar PDFS - Need optimization

We have a 5 MB and 7 MB and 8 MB PDFs that was exported from a layered PSD. Strangely, despite the modest file size, it lags on every device and in every viewer I have tried. The file eventually opens, so it isn’t corrupt, but the delay is unacceptable for everyday use and for sharing with clients... (Budget: $30 - $250 USD, Jobs: Adobe Acrobat, Adobe InDesign, Adobe Photoshop, Graphic Design, PDF, Photoshop, Print Design, Visual Design)