Home Depot offers the Fanmats MLB 26" x 42" Grill Mat in 29 styles (Chicago Cubs pictured), with prices starting at $27.99. (Amazon charges the same for several styles with free shipping for Prime members.) Opt for in-store pickup to dodge the $7.49 shipping fee. That's the lowest price we could find in any style by as much as $5, outside of the below mentions. Made in the USA, this vinyl mat is oil-, flame-, and UV-resistant and protects against grease spills and stains.
Of note, Amazon offers it in Tampa Bay Rays for $24.45, Miami Marlins for $27.37, or Seattle Mariners for $27.85, each with free shipping for Prime members.