It depends on what you want to do and your resources.
First is your location, if you are in a tier 1 country then you will have access to cheaper mobile data so you can set up bulk simcards and use the mobile data.
This will allow you to avoid paying for proxies. Simply have a script that will turn off then on aeroplane mode, then you have new IPs.
Being you are in a tier 1 country then you will also be more favoured by the socila media algorytms, meaning you can create your own accounts.
If you are not in one of these countries then you will need to buy accounts because creating accounts in other countries that the social media companies class as more high risk for spam and fraud then right off the bat you are going to have lower trust score.
Then you also have the issue of proxies.
You will need to buy proxies for each device which can get very expensive quick.
You will have a similar problem to the above paragraph with emulators or VMs.
Phone farms are the way to go no matter what. Just the excustion will varity depending on your resources and location.
As for phones themselves.
You want to be getting at least iphone X's or androids with android 11 and up but ideally 13.
Iphones will be easier to obtain and give a higher trust score with accounts because they are almost impossible to hack on where as android is easier. In my testing I have found accounts that have been created and run on Iphone seem to perform better and get results faster with less issues.
The other reason you want higher quality phones is resell value. If you change your mind and this is not for you, you can still sell the phones for close to or the same as what you bought them. Where are cheap phones (sub $100) you will be lucky to sell again because for 100 or 150 you can get a much newer phone with less issues.
