If I list a community market buy order I can select a quantity and price on the item in question. If I later decide to change the order I have to remove it and do it again. This has the negative effect of putting me to the back of the queue.
From steam support (emphasis mine):
How do buy orders choose which listing to buy?
When you place a buy order, the market first looks for all the cheapest items that can fulfill your order. Then the oldest listing (i.e. the seller who has waited the longest) is selected and purchased. If the items are listed in multiple currencies, the amounts are first converted into your currency before being selected (i.e. a 0.03 RUB listing has no priority over a 0.03 USD listing)
I just realised I misread the quote above as that is for sellers not buyers. However, I belive the behaviour is the same.
Is there any way I can change a buy order without removing it?