What condition are the tapes in?
As long as they are original, (ie. not copies of copies), haven't been excessively played so that the tape has stretched and don't have Macrovision you should be fine if you use a decent VHS playback machine.
Best indicator of whether you may need a TBC is if when you play the tape back on different machines you get flag-waving in the picture, (you also need to try playback to different TVs to check this, as TV timebase could be off if you just test with one). Flag-waving is where the edge of the picture on the TV is oscillating like the waves on water on the movements of a flag.
It's also better if you can play back the tapes from the machine they were recorded on, (depending on head condition), as any timebase fluctuation, (between different machines), is minimised.
More info on if you need a TBC here
FWIW, I use a ~15 year old mono Samsung VHS machine, (has had little use), which I connect to a Lifeview FlyTV 3000, (old TV card, ~10 years), and then IUVCS to do the recording.
I have used in the past: Sony Stereo Betamax VCR, Sony Mono Betamax VCR, NEC Stereo VHS VCR, Sony Mono VHS VCR.
Results have always been satisfactory except where the problem lies with the tape.
A cheaper option than a TBC to try may be one of the devices that "remove" Macrovision, they do this by cleaning up the timing signal, (as opposed to completely regenerating it as a TBC does), by removing any spurious signal components, (ie. anything that really shouldn't be there: spikes, etc).
Do you intend to do any video restoration after the capture, ie. colour correction, denoising, etc ?
If so, you might be better off using a capture card that has the option of software encoded capture rather than the increasingly common hardware based capture compression, (usually h.264 or MPEG2).