Soldering might be esoteric to some, but since my father is an avid and experienced, i kinda grew up seeing iron solders and things getting soldered.
I did my own backlight with only kitsch's tutorial and doing magic. The only thing I did wrong was fucking it up mildly the lcd screen (is still perfectly clear to use it, minor scratches here and there.
But since some prosound mods requires cutting the plastic, which is not that simple neither that hard, it might back off people who wants your Gameboy modded.
So as being repetitive, if you know you can do it, then do it and don't pay for the service and convenience.