anyone here print their shit before?

I have a nice photograph of me i wanted to get a poster of, as large as possible. the site is claiming that it will look fine at just 75 PPI which means I can have a pretty big poster, but im not sure I trust that as I heard 300 is the norm so 75 makes me think it'll be blurry as fuck. trying not to waste 30 bucks on a 'test' to see if it'd look good.

anyone print before? particularly at 75 DPI?