that's true we aren't always around to bid but since this question is in regards to high demmand items (items with at least one daily bid) submitting a "leave and hope" type bid in one of these type auctions is really only helping to raise the final price.
I say make the time or don't bid. This practice would help all the buyers in the long run and thus attract more sellers.
p.s.
RN, you must be the guy who alway beats my $1.01 last ditch bids.
I'll have to change that to $1.99!