The most fun you can have in audio is DIYing your own speakers

I have done a bit of this with Tannoy drivers in custom boxes and rebuilding the crossover with good parts. I purchased a pair of Tannoy Yorkminster SE for about 13 K.  I also ran across a pair of pro Tannoy15 inch drivers for about 1K, I bought a monstrous pair of DIY cabinets for $500 and rebuilt the Tannoy crossovers with quality parts for about $800.  At the end of it when myself and a friend were listening we both strongly preferred the 15's  in the DIY boxes at less than a quarter of the cost of the commercial offerings. 
 That is also a viable, easy and safe option for folks to go. Getting vintage Tannoy or altech drivers, building the boxes and re-doing the existing crossovers. 
Now I have a pair of altec 604's in the same boxes augmented with a pair of Homebuilt subwoofers and a pair of Foster T900 super tweeters.  True full range sound for about 4K. And when I go to the shows and listen to $40,000 speakers I still prefer mine.   I love the way a point source Soundstage's and images and now with augmentation on the top and bottom they don't suffer from the traditional weaknesses. 

 And I think it's on the money what Erik is saying about 10 times the cost of drivers. That's not the same as profit as it's true what TEO Audio was saying, there are other costs involved. 
 And everybody knows that cable manufacturers are the worst offenders when it comes to gluttonous profiteering 😇

He’s right...I paid something like 50 bucks a pair for some amazingly good Morrow ICs. I mean, yeah, they were on sale...still...50 bucks! Swine gluttons!

I thought I would chime in and say I have built Troels Gravensens Jensen Illuminator s.  This is a truly audiophile speaker.   Check his site out you can't go wrong.

I designed my speakers from the ground up.  Took about 18 months from preliminary designs for the cabinet, identifying drivers, multiple crossover designs, etc.  It can be a steep learning curve if you don’t go the kit route, but the forums listed above can help.  With the help of a woodturner in Iowa and a carpenter in Chicago I put together a very unique loudspeaker.  And as challenging as it was, it was a really rewarding experience.  The fact they sound great and punch way above their cost helps too.  Word to the wise, tho, it’s an addicting hobby—hard to stop building after your first pair.