i have a bit of a ritual when it comes to cleaning brushes, especially since i only really use acrylics, i saw it on another forum a loooong time ago when a similar topic was discussed and it seems to work
i rinse in a pot of clean water to remove most, wipe in kitchen paper, (never twist the brush and you gently pull it thro the paper or you will ruin the bristles) then whilst its still in the paper give it a little squirt of air brush cleaner and and gently pull thro again.....repeat til theres no colour being left on the paper.............then dip in water again to rinse and gently pull the brush through your fingers so it reforms the bristles into a 'brush' shape.....dont squeeze it so all the water comes out, idea is to leave it damp so that it will air dry leaving the bristles in the right shape
seems to work as i have brushes that are years old and still perfectly usuable
i always try and buy the decent quality brushes, i like HobbyCrafts range cos theres so much choice.....if i ever go in there or a model shop just to have a look round (normally whilst swmbo is shopping elsewhere

i will always buy a paint brush and a pot of paint......not often i buy a kit in a shop but always buying a brush or paint soon builds up a stock of them, and i dont think you can ever have enough brushes
a while back i took a punt by buying a set of 25 random artists brushes on ebay for about a fiver......you didnt know what you were getting, totally random......out of the 25 a few were useless cos of the shape or type but on the whole they have been a good buy.....the synthetic ones have been used for weathering, some of the natural ones are great for detail work