more about what? yes market bots exist, but they frankly aren’t very good, and not nearly as many people use them as you might think. it takes very little time and effort for a real person to scan their market orders and update as needed, and if nothing else is going on, a single person can easily babysit a hundred orders or more every 5 minutes.
multiply that by hundreds of players doing the same thing at the same time in market hubs, and of course your going to end up getting outbid often on high volume items.
as for why compressed omber costs so much more than silvery and gold varieties. thats a simple matter of supply and demand, omber is one of the primary sources for isogen, isogen is generally one of the limiting materials in manufacturing, so there is higher demand for it than for many others.
the supply of regular omber is also much higher than for the silvery and golden varieties, so if someone wants an order filled faster, or needs massive quantities of it, thats the one they are going to buy because there simply isn’t enough volume of the silver/gold.
higher demand leads to higher prices. and for large scale industrialists its more important to keep the production lines running in order to produce large volumes, than to put things on hold for weeks or months for an order to fill in order to maximize profit margins.