For what it’s worth, your code won’t work as expected (well, kudos if it does but it shouldn’t). The %s will happily munch up the rest of the string, meaning that $price will actually contain150.00</span>
Instead, %f could be used, which would also convert the 150.00 into a float rather than a string (whether that’s a good or bad thing depends on the intended use of the value).
Cups’ solution is nice and simple, though I would’ve gone for an ltrim rather than str_replace but my initial thought when reading the question was to clear away the tags with strip_tags too.