Acceptable to ask seller for option to return a component?

I have a lot of transactions here under my belt and only one time did the person as if they could return the product.  This was a pair of speakers that the person bought 6 months earlier.   He said he just didn’t like them.  I tried to be polite and told him I wasn’t a business and if he didn’t like them to sell them.  He still persisted so I pretty much told him to go pound sand.  He then tried to  change the positive feedback he gave me 6 months earlier to a negative one.   What gall to think I was going to give him his money back after using them for 6 months.  

Everything said above. I always tell my wife as I negotiate any major purchase- 

the worst thing that can happen is they say “no”.

stereo5 gives an example of why it is dangerous to accept returns. Yet another example of the 1%, probably 2% now, that ruin things for everyone. Over the last 25 years, I have had a few buyers want to return vacuum tubes because they didnt like the sound. 

You can ask, but most likely they will say no.

Many have a return policy with a 15% restocking fee 

Do your homework before you buy.  If you don't like it, resell it at little to no loss.