I haven't traded Tarkov items before, how does it work?

in flea or in raid

For bitcoin, gpus, or any items that aren't found in raid you can get someone to bring them in and then you stick them in gamma and nade yourself or go extract.

For flea there are certain items that have less fees when sold high. Bulbex for a mil charges about 200k fee, Tetriz for 500k, SSD's and some of the streamer items have less fees.