You have arrived. You're ready to take the leap and go old school with your sewing. Choosing the "best" one can seem difficult though.
Let me take some of the mystery right out of the search. Some sewing machines are more collectible than others (for good reasons) and therefore cost more.
However, when it comes to these five machines you will find that their reputation proceeds them and that their average prices tend to reflect that. Generally the better the condition and higher the demand the higher the price. Which brings us to the next point.
Looks don't matter much if the machine is proven to work. Among these 5, none is better than sewing than the others. You will save so much money if you don't have to have the "museum piece" or if you are willing to search out the good models that aren't trending and high in price at that moment - being flexible always saves you money. It's easy to get caught in a demand swell and ignore comparable models that will suit you just as well. If you are looking for a rewarding hobby or plan on light to even heavy use, you will be happy with any of these machines just find the best deal on any one of them, don't zero in on one specific model. Do a search for all of these. You could find a deal on one when you can't on the other.
I say this because I have sold most of these models and can vouch for their quality construction -their designs are all great and functional and boil down, more or less, to your preference. They are just different configurations of quality . If you like the look of one you can't go horribly wrong - once you've learned how to work your machine you wouldn't have it any other way.
Sticking with the "all Stars" though, the Singer models listed or similar ones, is important. Don't stray from the Singers. You may come across a beautiful old machine but have never heard of the manufacturer, you will also never see any parts for it. Singer dominated the industry in those days, they were the best, they put everyone else out of business and as a result you can find any replacement part or attachment for every machine they ever made. They are affordable and readily available.