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A good optician could have polished the Mt Palomar 200 inch in less time than I spent polishing my first 6" f7 mirror. My mentor could see that I was an impatient 15 year old so he made me polish out a severely turned down edge just to teach me patience. It also gave me a lot of confidence in my own abilities. With him riding me hard and giving a LOT of guidance, the mirror turned out as close to perfect as you could expect. I don't have a test figure for it but when it had a good coating and the seeing is perfect, I've had a 6mm eyepiece with a 3X barlow (500x) and the planets were crystal clear. If I'd had a shorter eyepiece combo, I suspect i could have gone higher.
It's had a crummy coating on it that doesn't do justice to the figure for more than 10 years but I want to rectify that soon.
I never did polish a second mirror but I've used the mechanical, manual and engineering skills and the patience and confidence he taught me continuously during the 35 years since both in my work in designing and modifying scientific instruments and at home in making lots of other stuff - both ATM and non-astro.
In 1978, a 6" mirror kit - two blanks - tool and mirror and full set of abrasives cost $22. A 6" telescope in the 1970's cost many hundreds of dollars which was the best part of a months pay at minimum adult wage.
So making a scope was a necessity in those days.
A skillfully made mirror will outperform a mass produced mirror but an unskillfully made mirror won't. Mine has given me enormous enjoyment and I'm about to re-juvenate that crappy coating and get it back to it's best. Be aware that you need to put significant time into making testers and other stuff before you can start polishing.
I recommend you do it, just be prepared to sink a lot of time into it. And remember that the aluminized coating alone will cost more than buying a mass produced mirror off the shelf today.
Joe
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