Other than just having some sales in there to look natural it will not benefit you in any way. It's not as though you will get extra sales because of being ranked higher or anything. You literally need hundreds of sales every single day to show up on top ten lists and need hundreds of thousands of sales overall.
So adding a few sales here and there is not going to do anything for you. You will just be paying a bunch of fees. honestly I cannot see any reason that you would do this. If you have a brand new shop and need a handful just to look open I understand that but that is the ONLY reason I can see you needing to do this.
If you really need to do it, the easiest ways to create an account, make a fake paypal, send it some money from your real one, just enough to make the purchase. That way you will have different payment details each time for the new accounts. No need to worry about IP's I run over 30 accounts from my house IP and I have used all of them to buy something or another from each of the shops. I also log in to around 50 other accounts on a daily basis to do promotion for some clients so needing proxies is a myth on Etsy.
I have NEVER had any problems in 7 years with Etsy, using multiple accounts or needing proxies.