IN MY CASE, ok ra palit ug ug afford nako ron. I love selling the old ones and love the part where you get to buy new parts (the smell of new hardware has always been extasy to me. Lol!) Plus the nice thing is you get to experience as many hardwares as you can. Low-end man na or extreme, used or brand new.
There are times na ka-timing ka ug barato kaayo pero nindot na gpu or psu. Its hard to let that pass by so you buy it and you get the opportunity to test it. If dili sya kaabot sa imo expectations, sell it.
BUT OF COURSE, for first timers, youd want (and actually need) to do it right the first time.