When the prices increased for haircuts in mid '01, I told my (back then) barber, I was going to start cutting my own.  I asked if they would like new clippers -- if I was going to buy some, the ones they were using were professional grade and would presumably last me a lifetime.  I asked if they would order a new set and sell their used clippers to me at whatever cost they deemed fair.  Since they were going to lose me as a customer regardless, they agreed and I got really good used (and cleaned) clippers for $30 iirc. 

They've paid for themselves many times over, and no sign of them ever wearing out.   FWIW:  the new clippers the barber shop ordered only cost $40 back in '01 for professional grade Wahl clippers. 

Probably couldn't just walk into any shop and get them to order clippers for you, but if you know someone who's in the business, you might explain to them that you don't want to take customers away from them (which is illegal 'here' without a license anyway), you just want a good set of clippers to cut your own hair with.  Even if they add a 'mark up' onto a good set, they are still cheap for the quality you get in return.