What is the most affordable equipment required for brazing?
The main difference between most torches is the maximum temperature it is capable of handling. So you can use propane as the fuel in MAPP torch (which burns hotter), for example.

The second difference will be whether it uses compressed oxygen, or just the air around it. If it uses compressed oxygen it will burn hotter.

Approximate burn temperatures ( as found on Wikipedia )


propane/air 3,630 °F (2,000 °C)
MAPP/air 3,670 °F (2,020 °C)
propane/oxygen 4,530 °F (2,500 °C)
acetylene/oxygen 6,330 °F (3,500 °C).


For more information read http://en.wikipedia.org/wiki/Oxy-fuel_welding_and_cutting

There are also some differences in the construction of torches that make them more suitable for use with some fuels over others.



For brazing, I would start out with one of those propane/air, or MAPP/air torches that just screw onto the end of those small bottles you find at hardware stores. They are usually packaged with a bottle of fuel, because they are so cheap.

If you then find that those don't put out enough heat, or you're constantly going through bottles of fuel, then upgrade.