Originally Posted by
bikemig
I'll be the one naysayer here.
For $125 or so, you can buy used a quality vintage MTB that with a change of tires and some repair work (old bikes always need some repair work) will make a fine gravel bike. Old MTBs make great repurposed gravel bikes and quality ones tend to be inexpensive on craigslist ($100 to $150 will get you a good one).
N+1?
$50 for new road tires and tuning the road bike.
$150 for the MTB to join the family off road.