I've bought basses of eBay. Valuable ones I've collected if within 100 miles or so and paid cash after testing (hadn't occurred to me to check that the TR is working or not - useful advice). I had a problem with one bass off eBay where the truss rod was broken (bought delivered, not collected) and simply returned it and got my money back - simples. Buy from sellers with 100% feedback and where the listing has been done with some thought with decent photos. Ask plenty of questions and ask for extra photos - a genuine seller won't mind this.