Inexpensive Sugar Free Vanilla Syrup?

So I love iced coffee, but all the sugar free vanilla syrups are outrageous now. Dollar tree used to have a couple different brands here and there but now they have none. Actually, people on eBay are literally selling those same ones for like $5+ now for profit lol Torani is like $7 now for one bottle.

Does anyone know if anyone sells inexpensive sugar free syrups, or even a good recipe to make your own? I tried making my own today with vanilla extract and monk fruit but it tasted horrible 😭 Thanks in advance!