Thanks for the great question!
When I started out as a newly licensed jumper, the best advice someone gave me was consult to my rigger or another more seasoned jumper before committing to buy something I found off the internet. The skydiving community is a relatively small community and chances are someone you know, knows someone that knows the seller or maybe the seller themselves. If that's not the case, try and do business through the drop zone the seller jumps at. I have used area drop zones to act as a 3rd party to broker gear purchases.
Prior to buying large ticket items such as containers, canopies or complete rig setups, you're going to want to have a rigger you trust inspect the gear. I strongly caution buying gear "sight unseen". You just never know what you'll end up with. Check with your instructors as well. Chances are they know your progression capabilities and what you can and should be flying and can point you in the right direction.
If you find something on an online forum that interests you, make contact with the seller to find out if it's still available. If it is, ask them if they'd be willing to ship it to either your rigger or the nearest drop zone for inspection. Generally this shipping charge is on you, unless the seller states otherwise. Once the inspection details are worked out, and you've decided to either buy or send back the gear, don't delay paying the seller or sending the gear back. Imagine if you were selling something and the buyer took forever to pay you or send the gear back if it's not being purchased?
so many choices
When purchasing gear online, it's ALWAYS a good idea to get all the details spelled out. Who's paying shipping? Who's paying for the inspection? What exactly included in this sale? Shipping details? Believe it or not, I've had jumpers say they've purchased gear and were surprised when they received it and something wasn't included. Example, canopies generally aren't sold with risers, d-bags or pilot chutes. Canopy and lines; that's it. Reserves should be accompanied by their data cards showing their history. Details like these that being a newer jumper you may not know. Again, always consult your rigger, instructor or another trusted jumper that can point you in the right direction.
"I bought it with less than 400 jumps, put 78 on it. Has original dacron lines with red centre crew lines, plenty of life left on it. Comes with risers with rsl, velcro toggles and dive loops. 800 feet snivelly openings, flies like a spectre, lands like a spectre. Buyer pays shipping."
Don't try and buy something on your own without asking first. Even past your A license, it's never a bad idea to ask. It can only make you a better informed jumper, right? Have fun jumping with your friends and good luck with the gear search!
Thank you Amanda for submitting your question and as always thank you Shauna for providing some good advice.