You could source a pair of gigabit media converters and a length of fiber on Amazon for about $100. Just use the media converters to extend the Ethernet port from where the Internet hands off in your house over to your office. You can affix the fiber along baseboards and up over door frames with adhesive cleats and zip ties, or those nylon staples on a nail they use to tack down coax cable.
If you're willing to spend a little more on the fiber for a custom color, you can probably even order the fiber in a more neutral color than SMF yellow to blend into the trim better.