I used to buy up old bikes, break them and sell them on ebay, did quite a few of them for a while and it worked quite well until everyone and his mother started using those stupid last minute bidding apps. Now I dont bother. Nowadays if you try to sell a part on ebay you put it on for a 7 day listing at a pound expecting it to go for whatever anyone thinks its worth, might be a pound, might get a bidding war, who knows, but instead you get no bids whatsoever but about 100 'watchers'. These watchers are the ones using the last minute bidding apps now instead of bidding! If you watch your own item in the last few seconds you see about 10 or 15 bids appear as all the apps try to get their bids in, but ebay cant cope with all those bids at once so half of the bidsdont register in time. The outcome? A seller that gets sod all for his part and loads of unhappy bidders that email the seller wanting to know why the winning bidder got it for a tenner when they had a bid of 20 quid in their bidding app. I got fed up with all the hassle in the end, being accused of ending the auction in the last second etc and I no longer sell on ebay. Shame, cos I never once got bad feedback from someone I sold too, just agro from all the hundreds of sheep that used those stupid bid sniper apps.
Nowadays, if I buy from ebay I stick in my highest bid early (say £40) and then leave it. It will sit at a pound for the duration of the auction until the last 6 seconds then it will shoot up as ebay tries to proccess everybodies bids. If I win its good, but if not then at least I have got no chance of being in a bidding war and paying over the odds!