Betfair are doing 8 places but only 1/5. If you want a long odds punt I’d go for one of Zach Johnson @ 100/1 (former winner, class act, getting on a bit and not that long off the tee though), Jimmy Walker (140/1, major winner with decent Masters form - 2x top 20, 2x top 40 in the last 4 years), or Pat Perez (175/1, 18th last year, played the best golf of his career in the last 18 months. Might be a bit nutty.)
Disclaimer: They’re all 100+ for a reason…