I'm not familiar with the Aztec line, except some people despise them and some love them. I recommend the Badger 100LG dual action available for $64.95 at
Dixie Art. There are others who will recommend Paasche and Iwata, all of which have models (and all of which are available from Dixie Art) well under the $100 limit. A good deal is the Badger 150 Pro Set which includes Fine, Medium and Large needles & tips, color cup, 3/4 oz jar w/adapter, 2 oz jar & a 6' braided hose for only $74.95. This is the same AB as the 100LG except it's a siphon fed brush. I own both. The big difference between them is that the 100LG can spray slightly finer lines due to the simple fact that it can spray using less pressure. The tips & needles (in fact all parts) are interchangeable between the 100/150 line. Only the main body are different, and that only because of the different methods of holding the paint.