If you want one fast, then go for the Walmart Brother. If you've been reading a lot about inexpensive machines on here, they are very popular. We have had a lot of threads on them. I have three of them myself, at different places, and they are workhorses and are not fussy about thread. Even the Coats and Clark made in Mexico zips right through them. They do have a zigzag function.
Vintage are fun to have, but, you can't always count on walking into a thrift store and finding one in good enough shape to start sewing. If you have plenty of time to look, that's another story.
Shows are good too, if there is one near enough to you soon enough, unless you can't wait til the next one. Where I live now, no shows are close. Have to travel. That adds to expense.
If you've read on the vintage forum here, you can see that sometimes eBay or shop goodwill don't pack well sometimes, which means you have to look for a machine you like, win the bidding, and then trust the seller to pack well. Not impossible, but, if you want something pretty soon, that doesn't seem like a good option.
Good luck on your quest and let us know what happens!!!
If it were me, I'd get the Walmart Brother. You can always return it if it doesn't do what you want it to.