For the cheap brushes I may recommend you a Costal Scents. They have a lot of nice affordable synthetic brushes. I think they have Dior synthetic kabuki, for something like 10 $.
As to the TBK I intend to order from them, while their powders are cheaper than at TBK and they have good customer services. However now I'm waiting for them to get a silk powder in stock, cos I want to add it to my order.
If you are on alow budget you might also want to consider the kabuki or flat top brush of Silk Naturals, I have bought both of them (they are around 10 or 11 USD each) and they really are extremely soft synthetic hair (I find synthetic brushes softer and better to apply mmu, but then that's just me )
I've ordered from TKB...but only jars...their CS is pretty good. The prices of their brushes are really low but I've read some less than positive comments about them on Delphi...like shedding and being abit scratchy. I personally would go for Coastal scents brushes if you're on a budget.
I can't see your links, so I'm not sure which specific products you're interested in... but I've ordered from TKB before. They had a minimum order requirement. I bought some silk powder, pearl powder, kaolin clay, jojoba oil and some sifter jars. I was very happy with my order and would order from them again. (I also got small and large plastic scoops included for free with my order... not a big deal but they are very nice to use when mixing mineral colors together.)
No, don't do it! I ordered the whole set of brushes when they were first available, and almost none of them are usable. There's a whole huge thread about this on MMM. I thought the company itself was very professional, and I wanted to love the brushes, but they're completely unacceptable for use with mineral makeup. Waste of money. :-(