DIY On-Wall Mains

I have a friend that is looking for on-wall mains that have a decent amount of output (more than his crappy little HTIB speakers). Does anyone know of any good plans to build a set?

He is not looking to break the bank on a pair of speakers, so I thought maybe the DIY route might yield a better output/price ratio.

If there are no DIY solutions, I would be interested in pointing him to some commercial options. I am still trying to convince him to go with floorstanding speakers, but that may be a long shot.

Any help is appreciated!

I could probably convince him to spend $100 per speaker if that would yield good results. However, it that is still too low, what kind of commercial products would you recommend?