From what I have come to see, Blasters are only for a certain audience. They are not the most well rounded quads but are decent quads for the people that they are geared towards.
They are small, lightweight, simple to work on quads. They have some good pep as does every 2 stroke but not the fastest quad you're going to find. I find them to be very good trail quads because they are small and lightweight. You can whip them around everywhere and if you happen to find mud that's too much for it, you can simply just lift it right out with the help of a buddy.
$1000 can get you a decent blaster. Around $600 you can get a used pipe, some good reeds, cylinder porting, and head machining (see Ken O'Connor Racing for the machine work. He's the man when it comes to Blasters and very reasonable prices). Those four things along with re-jetting your carb for the work done will get your buddies on 400s wondering how such a small quad is keeping up (and passing if you're a good rider). After that, the best way to get faster is with suspension and that's gonna cost. Best to find something used and get revalved if you are on a budget but even that's gonna cost you a good amount.
Ultimately its whatever you are more into. Do you want a 4 stroke that has power everywhere and more well rounded but if it breaks down then you gotta spend a lot of money and time to fix or do you like the riding style of a 2 stroke that is more technical and peppy but easier maintenance? You can typically find Blasters pretty cheap but when you put money into one, you usually won't get it back when you sell it. So if you plan on putting a lot of money in it, you better get your money's worth out of using it because you won't when you go to sell it. I'm keeping mine forever so I don't mind all the money I've put in it.
Blasters are not for everyone but perfect for some.