I have bought 90% of my gear through LL and here. I've always used wire-transfer (to avoid fees, quick verification, bank reviewed) and a contract if the seller is in the USA. If the seller is out of the country I tend to go through eBay.
I typically talk with the seller first (email, phone or txt), negotiate a price and a create a list / quality of all the gear. I then write up a "Bill of Sale / Sale Agreement" that has the list of equipment, both our names and addresses, along with how payment will be made. It will also include that details of how / when the shipment and tracking will be provided (typically on the same day of the wire).
I then coordinate when we would like to process the sale, we both sign the agreement, I make a PDF of the document and send us both copies. I then take the wire information and contract to the my bank, have them review it and we process the wire. I then call or text the seller with the wire confirmation, asking them to verify with their bank that they see it. They return call or text me the same day and provide me the tracking number for shipment (before COB my timezone).
As I said I've done this for lots of photography equipment as examples: my P45+ / AFDIII / Lenses, RX67 IID + lenses, Lens purchases and RM3Di body.
I have also gone the route that other have using paypal "gift" but, I've used that more for server, storage and networking gear as those individuals tend to be more of independent consultants or IT engineers who want to document the sale for tax purposes.
So, if you follow the advise that most people have stated about checking on the seller, seeing if they've sold other items (check here and LL - they sometimes post in both but, have more history in one vs. the other) you should be in good shape. Just do you due diligence and try to purchase in country as much as possible if you want to do a wire transfer.
Please note I've never had a seller ask for a wire transfer, I've always offered it so that they feel comfortable with a fast and reliable transaction, especially if paypal fees was going to be an issue or concern.
Just thought I'd share my experience... oh and where I come from in California "Bill of Sale Contracts" can be legally binding. So, you do have some legal recourse (in the USA).