Ive never used a sniping program myself, but have bought a lot on ebay. Before I purchase anything (mostly records) i will watch that item run through several times, unless its rare and i dont expect to see it again.
but ive found that something that usually goes for, say $10, one or two will regularly slip through at $5. You just gotta be patient.
a vast majority of my bids get sniped at the last minute, like at least 9 out of 10. and its hard to pick your max price. if i said i wouldnt go above $20 for that, and then it ended $20.50, I cant help but think "whats another 50 cents, damn i shouldve bid a little more".
i did by a rather large bag end soundsystem, and only one by having a faster refresh time. that was invigorating.