Hi!
In the reply #11 here I recommended the GW Instek AFG-2005 function generator as a cheap option. I still own it and now I decided to open it's cover and take a look inside only out of curiosity. To be honest, I was expecting to see a much lower quality PCB. Since I could not find any photos of it's guts on the internet, I think it's a good idea to upload them here, maybe someone sometime in the future will be curious and he will google them.
Keywords: GW Instek AFG-2005 teardown inside photos