Should I hire a Cornwall marketing agency or do it myself?

Depends on three things: time, technical comfort, and how quickly you need results. DIY works if you've got 5+ hours a week, you're comfortable learning Google Business Profile, basic SEO, and content writing, and you're OK with a 9 to 12 month timeline. Hiring an agency makes sense if your time is worth more than £50 an hour to the business, you'd rather those hours go into running your business, and you want results in 4 to 6 months. A realistic Cornwall small-business marketing budget is £500 to £1,500 a month for managed SEO + content + GBP. Below that, you're better off starting DIY with a one-off audit (£599) and a strong Google Business Profile.