If you do a high starting bid like that and they never outbid you, you get refunded the gold, i.e. you bid 1m, they bid it up to 200k, you get 800k back.
Lots of items get put up for vendor/low bids with no buyouts. A lot will wait until the timer gets to <1 minute to bid on them. To try and avoid getting 'sniped' try using odd amounts, for instance they will usually bid in even amounts like 250k, so a bid of 251k can secure it, or bid a large amount that you feel comfortable paying in full, just in case they do bid you up that far.