Personally, with a range of quotes, I normally eliminate the top (often they are busy and don't need the work) and the bottom as are likely to be under pricing and will take short cuts when they realise. Of the middle quotes I make a judgement call on the guy.
But actually, on that scale of job, I'd take soundings as to the best local guy who works on reputation and recommendation and work with him as preferred contractor with no other quotes.
I did that last year on a roof leak that has been a 20 year problem on our loft conversion. 3 guys had failed to solve. The Best Rep local guy, diagnosed problem, took me up and showed me and gave a fully itemised quote with itemised "if on reveal" caveats. Ie a price range, with a "minimum and not more than".
Price was ultimately at low end if range, and for the first time in 20 years roof was fully weather tight over last winter.
£75?
How much an hour is he valuing his time? Quoting time. Travelling. Job time. Admin time. Tool. Materials. Insurance.
When I gave up (hobby) jobbing gardening 8/10 years ago I was charging £22 per hour.