Butane Torch- want advice

I have started working on a brass Locomotive kit I have had for LOTS of years. I am thinking of getting one of the small butane torches for soldering. Any advice would help a lot.
Kit is in 1/4" = 1 Ft. so some parts are very small. Old Weller soldering gun is OK for some of it. Would like to keep price around $30.00.
Thanks,
Mike