I recently saw a Game Doctor SF7 for sale for 50 AUD in one of the second hand game shops in Australia.
No idea how much RAM it has onboard. I'm used to using these kinds of copiers, as I've got a Doctor V64 for my N64.
Would it be worth it in conjunction with a
GoTek floppy emulator?
It should be OK, but not very convenient compared to a flash cart. I have a Game Station which is based on the SF7, but I haven't picked up a floppy emulator yet. Mine has a CD-ROM so I'd only need it for saves, so one floppy disk has me covered (assuming it still works).
Most of the SNES library is 8Mbits and under, but larger than that requires them to be split across multiple disks. But when you load the game into RAM, it stays there until you unplug the SF7. If you have a small number of games you want to play, that's convenient enough. If you want to have access to any and every SNES game whenever you want, it's probably going to be a pain. The filenames are weird, you basically only get 3 letters/digits that you can use.
Smallest memory they come in I think was 16Mbits. It supports save states too and that works pretty well, it's easy to screw up the audio though since it can't save the state of that, works OK with most games anyways when I tried it.
I think it really depends on how much it would cost you to get something like a Super EverDrive. I'm just guessing it would probably cost half as much or less so it might be worth it if you are willing to fool around with Floppy Disks or if you have a suitable PC to use the Parallel Link feature for ROM transfer.
I think all GDSF7 units came standard with 32 megabits. However it is possible to remove and install a smaller memory board if someone felt like it. If the unit is functioning fully you should probably get it.
I found one recently and bought it for the nostalgia. It works great with the floppy emulator.
The unit itself cost about the same. I then proceeded to spend a bunch more on RAM upgrades, DSP adapter, and eventually a CD7 unit.
Good luck!